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[[File:IBM PS2 Model 30 286 front view.jpg|thumb|300px|An IBM PS/2 Model 30 286 (8530-E series). The 286 machines are the ones with a voltage selector switch on the rear and a Dallas RTC module on the planar. (Image: DigitalIceAge, CC BY 4.0, via Wikimedia Commons)]]
[[File:IBM PS2 Model 30 286 front view.jpg|thumb|300px|An IBM PS/2 Model 30 286 (8530-E series). (Image: DigitalIceAge, CC BY 4.0, via Wikimedia Commons)]]
This guide documents preventive maintenance on the '''[[IBM PS/2 Model 30]]''' (machine type 8530), covering both the original Model 30 8086 (8530-002 and 8530-021) and the later Model 30 286 (8530-E01, E21, E31, E41). The Model 30 is a desktop-form-factor PS/2 with no integrated CRT, unlike the [[IBM PS/2 Model 25|Model 25]], so the system unit can be opened and worked on at the bench with far less electrical risk.
Routine maintenance on the '''[[IBM PS/2 Model 30]]''' (machine type 8530) covers two machines: the original 8086 Model 30 (8530-001, -002, -021) and the Model 30 286 (8530-E01 to E41). Both are desktop system units with no built-in display, so the work is on the planar, the riser card, the power supply and the drives.


== Safety Warning ==
== Safety ==


The power supply rectifies the mains directly and its bulk capacitor holds that charge after the lead is pulled &mdash; roughly 170 V on a 120 V mains, roughly 325 V on a 230 V mains. Before any work inside the supply's shell:
The power supply rectifies the mains, and its reservoir capacitor holds about 170 V on 120 V mains or about 325 V on 230 V mains after the plug is pulled. Before working inside the supply, unplug it, discharge that capacitor through a resistor and confirm with a meter that it has fallen to a few volts.


# Power off and unplug the mains lead.
On a Model 30 286, set the voltage switch on the rear to 100–125 V or 200–240 V before plugging in the power cord.<ref name="hmr286">IBM, ''IBM PS/2 Model 30 286 Hardware Maintenance Reference'', S64F-3988-00, March 1990. Hosted on this wiki as [[IBM PS2 Model 30 286 Hardware Maintenance Reference]] ([[:File:IBM PS2 Model 30 286 HMR.pdf|PDF]]). Sections 1.1.2 (power-on password, J13), 1.2.2 (CMOS RAM and battery), 1.2.6 (keyboard and pointing-device connectors), 2.2 (diskette drive identification and media compatibility), 3.1 (power supply switch and under-voltage sense levels), 3.2 (POST), 6.3 (park the heads before removing a fixed disk), 6.14 (1070 clock module), 7.4 (system board locations), 7.6 (1/3-height diskette cable).</ref> The 8086 Model 30 supply accepts 120 V or 220/240 V without a switch.<ref name="tr30">IBM, ''IBM Personal System/2 Model 30 Technical Reference'', January 1987. Hosted on this wiki as [[IBM PS2 Model 30 Technical Reference (January 1987)]] ([[:File:IBM PS2 Model 30 Technical Reference Jan87.pdf|PDF]]). Keyboard and pointing device controller, p. 1-9; interrupt listing, Figure 1-9; I/O address map, Figure 1-12; diskette drive connector, Figure 1-97, p. 1-105; fixed disk connector, pp. 1-106 and 1-107; Section 3, "Power Supply", pp. 3-3 to 3-6 (input, outputs, sense levels, power-good signal, P3 and P4 pin assignments).</ref>
# Bleed the bulk capacitor through a resistor across its terminals (1&nbsp;kΩ / 5&nbsp;W is the usual workshop choice).
# Confirm on a DC range that it is down to a few volts.


If your machine is a Model 30 286, '''check the voltage selector switch on the rear before plugging the cord in'''. It must be set to the 100&ndash;125 Vac or the 200&ndash;240 Vac range to match your supply.<ref name="atpower">Louis Ohland, Tomáš Slavotínek ''et al.'', "8525 / 8530 Power", Ardent Tool of Capitalism, https://www.ardent-tool.com/8530/Power.html. Transcribes IBM's Hardware Maintenance Service data for the 8525 and 8530: the P3/P4 and J7 connector measurement limits, the minimum under-voltage sense levels, the power-good range and the dead-system isolation procedure, and the warning that the manually-switchable supply must be set before the cord is plugged in.</ref><ref name="ann189035">IBM Announcement Letter 189-035, ''Personal System/2 Model 30 286 (8530-E01)''. Gives the 90-watt dual-voltage power supply with a switch on the rear, the 90&ndash;137 Vac and 180&ndash;265 Vac input ranges, the 10 MHz 80286, VGA graphics and the 1.44 MB diskette drive.</ref> The 8086 Model 30's supply is the internal-sensing type and has no switch.<ref name="ann187048">IBM Announcement Letter 187-048, ''IBM Personal System/2 Model 30 (8530-002, -021)'', 2 April 1987. Gives the "Universal 70W power supply, with internal sensing, for worldwide usage", and the 8530-002 (two 720 KB diskette drives) and 8530-021 (20 MB fixed disk with integrated controller plus one 720 KB diskette drive) configurations.</ref>
There is no CRT in the system unit. For a PS/2 display, see [[CRT Discharge Procedure]].


There is no CRT inside the Model 30 itself, so the anode-discharge procedure needed on the [[IBM PS/2 Model 25 Maintenance Guide|Model 25]] does not apply unless you are servicing the matching PS/2 display, in which case see [[CRT Discharge Procedure]].
== Identifying your model ==


== Identifying Your Model ==
The machine type and submodel are on the rear label, for example "Type 8530-E21".


{| class="wikitable styled-table" style="width:100%; text-align:center;"
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''Model 30 generation identification'''
|+'''Model 30 and Model 30 286'''
! Marker !! Model 30 8086 !! Model 30 286
! !! Model 30 !! Model 30 286
|-
|-
| Machine types || 8530-002, 8530-021 || 8530-E01, E21, E31, E41
| Submodels || 001, 002, 021 || E01, E21, E31, E41 (E0R, E2R with a 50-key keyboard)
|-
|-
| CPU || Intel 8086-2 at 8 MHz, at planar U10 || Intel 80286 at 10 MHz, at planar ZM36 (PGA socket on early boards, PLCC on later)
| Processor || 8086-2 at 8 MHz, U10 || 80286 at 10 MHz, ZM36
|-
| Chipset || IBM gate arrays || VLSI VL82CPCAT-QC, at ZM2&ndash;ZM6
|-
|-
| Video || MCGA || VGA
| Video || MCGA || VGA
|-
|-
| Riser || three 8-bit ISA slots || 16-bit ISA
| Clock || MM58167AN at U16; 3 V cell soldered to the riser || DS1287 clock module in a socket at ZM35
|-
| Extra bus power connector || absent || present (J14, 4-pin, feeds the 16-bit bus)
|-
| Real-time clock || NS MM58167AN at planar U16, battery on the riser card || Dallas DS1287 module at ZM35, cell sealed inside
|-
|-
| Diskette drive as shipped || 720 KB || 1.44 MB
| Diskette drive || 720 KB || 1.44 MB, "1.44" on the eject button
|-
|-
| Power supply || 70 W, internal sensing, no voltage switch || 90 W, dual voltage, switch on the rear
| Power supply || 70 W, no voltage switch || 90 W, voltage switch on the rear
|}
|}


Sources for this table: the planar designator maps,<ref name="at8530planar">Louis Ohland, Tomáš Slavotínek ''et al.'', "8530 Planar (8086)", Ardent Tool of Capitalism, https://www.ardent-tool.com/8530/Planar.html. Gives the "P-PLANAR" P/N 61X8823 designator map, the two Greenock planar variants (P/N 33F4888 and FRU P/N 33F8474 / P/N 33F4871), the ROM image list, the riser card part numbers (61X8864, 61X8910) and its B1 3 V lithium battery (Panasonic BR-2/3A), the note that reference designators are largely consistent across all 8086-based Model 30 and Model 25 planars, and IBM retain tips H007157, H043664, H067282 and H094152.</ref><ref name="at8530planar286">Louis Ohland, Tomáš Slavotínek ''et al.'', "8530 286 Planar", Ardent Tool of Capitalism, https://www.ardent-tool.com/8530/Planar_286.html. Gives the full 8530-286 planar designator map (VL82CPCAT-QC chipset at ZM2&ndash;ZM6, VL16C451 at ZM9, DS1287 RTC/CMOS at ZM35, 8042/8742 keyboard controller at ZM33, 286-10 CPU at ZM36), the early PGA and later PLCC builds with FRU P/N 34F0046, the J13 password-override jumper and IBM retain tip H036143.</ref> IBM's announcement letters,<ref name="ann187048" /><ref name="ann189035" /> and IBM's ''Technical Reference''.<ref name="tr30">IBM, ''IBM Personal System/2 Model 30 Technical Reference'', January 1987. [[:File:IBM PS2 Model 30 Technical Reference Jan87.pdf]]. Section 1 lists the system board's integrated I/O functions, including "Real-time clock with battery", the I/O address map (real-time clock at hex 00B0&ndash;00BF and 00E0&ndash;00EF), and the diskette and fixed-disk connector pin assignments. Section 3 "Power Supply", pages 3-3 to 3-6, gives the 70 W rating, rail currents, regulation tolerances, under-voltage sense levels, power-good characteristics and the P3/P4 pin assignments.</ref>
Sources: IBM's announcement letters and ''Hardware Maintenance Manual'',<ref name="ann187048">IBM Announcement Letter 187-048, ''IBM Personal System/2 Model 30'', 2 April 1987, text at [https://www.ardent-tool.com/8530/187-048.txt ardent-tool.com]. Models 002 and 021 with 720 KB drives, the 70 W "Universal ... power supply, with internal sensing", and the Starter Diskette.</ref><ref name="hmm">IBM, ''IBM Personal System/2 Hardware Maintenance Manual'', S52G-9971-02, October 1994. Hosted on this wiki as [[IBM Personal System 2 Hardware Maintenance Manual (S52G-9971-02, October 1994)]] ([[:File:IBM PS2 HMM S52G-9971 Oct 1994.pdf|PDF]]). Error codes 160–170 with FRU order and the lithium battery caution, p. 36; Models 30 and 30-286 power connector pin assignments, p. 138; Model 30 parts, p. 228; Model 30-286 parts, p. 230; system specifications for 8530-001 to E41, p. 435.</ref> the HMR<ref name="hmr286" /> and the planar maps.<ref name="at8530planar">Louis Ohland, Tomáš Slavotínek ''et al.'', [https://www.ardent-tool.com/8530/Planar.html "8530 Planar (8086)"], Ardent Tool of Capitalism. Designator maps of planars 61X8823, 33F4888 and 33F8474 (F1 "Mouse fuse?", F2 "Keyboard fuse?", F2 missing on the second Greenock board); riser card P/N 61X8864 and 61X8910 with the B1 BR-2/3A cell; and the full text of IBM retain tips H007157, H043664, H067282 and H094152.</ref><ref name="at8530planar286">Louis Ohland, Tomáš Slavotínek ''et al.'', [https://www.ardent-tool.com/8530/Planar_286.html "8530 286 Planar"], Ardent Tool of Capitalism. Designator maps of the PGA and PLCC (FRU 34F0046) planars, including F1, J13 password override and ZM35 DS1287, and IBM retain tip H036143.</ref>
 
The machine type and submodel are printed on the rear panel label, for example "Type 8530-E21".


== Planar Layout ==
== Planar layout ==


The 8086 planar exists as the original "P-PLANAR" P/N 61X8823 and two later Greenock builds, P/N 33F4888 and FRU P/N 33F8474 (P/N 33F4871). The layouts look nothing like each other, but '''the reference designators are largely consistent across all of them''' &mdash; and across the 8086-based Model 25 planars too, which makes this map useful on either machine.<ref name="at8530planar" />
The 8086 planar was built as P/N 61X8823 and in two later Greenock versions, P/N 33F4888 and FRU 33F8474. The reference designators are largely the same on all three and on the 8086 [[IBM PS/2 Model 25|Model 25]].<ref name="at8530planar" />


{| class="wikitable styled-table" style="width:100%;"
{| class="wikitable styled-table" style="width:100%;"
|+'''Model 30 8086 planar &mdash; principal designators'''
|+'''Model 30 (8086) planar'''
! Designator !! Device
! Designator !! Device
|-
|-
| J1 / J2 || Mouse / keyboard connectors (Mini-DIN-6, not interchangeable)
| J1, J2 || Mouse and keyboard connectors
|-
|-
| J3 || Parallel port (DB-25)
| J3 || Parallel port
|-
|-
| J4 || Video connector (HD-15)
| J4 || Video connector (HD-15)
Line 64: Line 54:
| J7, J9 || Power connectors
| J7, J9 || Power connectors
|-
|-
| J10 || 2-pin keylock header
| J10 || Two-pin keylock header
|-
|-
| J11 || 44-pin fixed-disk connector
| J11 || 44-pin fixed-disk connector
Line 70: Line 60:
| J12 || 40-pin diskette connector
| J12 || 40-pin diskette connector
|-
|-
| J13 || Dual 30-pin SIMM socket
| J13 || Dual 30-pin memory socket
|-
| F1 / F2 || Mouse and keyboard fuses (combined into F1 on the later alternative Greenock board)
|-
| U5 || Inmos IMSG171S RAMDAC
|-
| U8 || Intel P8253-5 timer
|-
| U10 || Intel 8086-2 CPU, 8 MHz
|-
| U13 || 8087 coprocessor socket
|-
| U16 || NS MM58167AN real-time clock
|-
|-
| U17, U20 || ROM BIOS (even / odd)
| F1, F2 || Probably the mouse and keyboard fuses (F2 absent on the second Greenock board)
|-
|-
| U18 || NEC µPD765AC diskette controller
| U10 || Intel 8086-2
|-
|-
| U19 || 8237A DMA controller
| U13 || 8087 socket
|-
|-
| U27 || NS8250AV UART
| U16 || MM58167AN real-time clock
|-
|-
| SP1 || Piezo speaker
| U17, U20 || ROM BIOS
|-
|-
| Y1 / Y2 / Y3 || 14.31818 MHz / 25.175 MHz / 48.000 MHz oscillators
| SP1 || Speaker
|-
|-
| Y4 || 32.768 kHz crystal (real-time clock)
| Y4 || 32.768 kHz clock crystal
|}
|}


On the 286 planar the numbering changes to a ZM prefix: ZM2 VL82C100 peripheral controller, ZM3 VL82C102A memory controller, ZM4 VL82C103A address buffer, ZM5 VL82C104 data buffer, ZM6 VL82C101B system controller, ZM9 VL16C451 parallel/UART, ZM19 µPD765AC-2 diskette controller, ZM33 8042/8742 keyboard controller, ZM35 Dallas DS1287 RTC/CMOS, ZM36 the 286 CPU. Power arrives at J7 and J14, and J13 is the password-override jumper.<ref name="at8530planar286" />
On the 286 planar, IBM's HMR locates J3 parallel, J5 serial, J6 bus adapter (riser), J1 pointing device, J2 keyboard, J9 and J10 memory packs, J11 fixed disk, J7 and J14 power, J4 display, J13 password override, ZM36 processor, ZM35 clock module, ZM1 coprocessor and J12 diskette.<ref name="hmr286" />


== Opening the System Unit ==
== Opening the system unit ==


Tools: a Philips screwdriver, an anti-static strap and a plastic spudger.
Tools: a screwdriver and an anti-static wrist strap. IBM's steps for the Model 30 286:<ref name="gto30286">IBM, ''Personal System/2 Model 30 286 Guide to Operations'', first edition, September 1988. Hosted on this wiki as [[IBM PS2 Model 30 286 Guide to Operations]] ([[:File:IBM PS2 Model 30 286 Guide to Operations.pdf|PDF]]). "Cover Removal", p. 2-2; "Power-on Password Reset", pp. 3-4 and 3-5.</ref>


# Turn off the system unit and every external option.
# Turn off the system unit and every external device.
# Unplug the system unit's power cord from the outlet, then the cords of any external options.
# Unplug the system unit's power cord, then the cords of any external devices.
# Remove all cables from the rear of the system unit.
# Remove all cables from the rear.
# If the machine has a cover lock, unlock it and remove the key.
# If there is a cover lock, unlock it and remove the key.
# Loosen the '''two cover screws''' and lift the cover off.<ref name="gto30286">IBM, ''Personal System/2 Model 30 286 Guide to Operations'', first edition, September 1988. [[IBM PS2 Model 30 286 Guide to Operations|IBM PS/2 Model 30 286 Guide to Operations]] ([[:File:IBM PS2 Model 30 286 Guide to Operations.pdf|PDF]]). "Cover Removal", page 2-2, and "Power-on Password Reset", pages 3-4 and 3-5, which locate the J13 jumper on the system board and describe moving it between the first-and-second and second-and-third pin positions.</ref>
# Loosen the two cover screws and remove the cover.


[[File:IBM PS2 Model 30 286 open top.jpg|center|thumb|640px|A Model 30 286 with the cover off. The drive cage sits over the planar, the power supply alongside it, and the riser card at the rear. Drives and cards are held by plastic captive push-pin fittings, not screws. (Image: DigitalIceAge, CC BY 4.0, via Wikimedia Commons)]]
[[File:IBM PS2 Model 30 286 open top.jpg|center|thumb|640px|A Model 30 286 with the cover off. (Image: DigitalIceAge, CC BY 4.0, via Wikimedia Commons)]]


Inside, the drive cage sits over the planar and the supply is alongside it; the riser card mounts at the rear. Cards on the riser and the drives are held by IBM's plastic captive push-pin fittings. '''Lever these with a plastic spudger, never a metal screwdriver''' &mdash; the pins are brittle with age and snap, and a broken captive pin means the drive cage no longer locates properly.
IBM's removal order for the system board is adapters, bus adapter (riser), memory packs and coprocessor, then all cables. The power supply comes out after the cover, the rear cover and the bus-adapter support.<ref name="hmr286" />


== Regular Cleaning ==
== Cleaning ==


* Soft brush and low-pressure compressed air for the planar, riser, drives and supply vents. Hold any fan blades still by hand while blowing, so the fan is not spun beyond its rated speed.
* Brush and blow dust out of the planar, riser, drives and supply vents with low-pressure air. Hold any fan still while doing so.
* Clean the Mini-DIN-6 keyboard and pointing-device connectors with a deoxidising contact cleaner on a foam swab, sparingly.
* Clean the keyboard and mouse sockets and the DB-25 connectors with contact cleaner on a foam swab.
* Clean the DB-25 parallel and serial connectors.
* Check the planar for leaked electrolyte, and the diskette drive board more closely: PS/2 drives have no dust shutter and collect dirt, and their surface-mount electrolytics leak.<ref name="atcommon60">[https://www.ardent-tool.com/60_65_80/Common.html "60, 65 SX, and 80 – Common Devices"], Ardent Tool of Capitalism. Peter Wendt on ALPS and Mitsubishi PS/2 diskette drives: both collect dust through the slot, which has no shield; the Mitsubishi 355 collects dirt on the head actuator spindle; ALPS drives lose the head-damper pad; Mitsubishi drives have capacitors that cause 6xx errors.</ref><ref name="at8525planar">Louis Ohland, William R. Walsh, Tomáš Slavotínek ''et al.'', [https://www.ardent-tool.com/8525/Planar.html "8525 Planar"], Ardent Tool of Capitalism. William Walsh on PS/2 diskette drives (dust, and replacing every surface-mount electrolytic on the drive board), the undocumented 1.44 MB support of the 8086 Model 25 and Model 30 with Sony drives, XT-IDE as the storage upgrade, and the Model 25 8086 using a different power connector from the Model 30 8086.</ref> See [[IBM PS/2 Model 30 Capacitor Replacement Guide]].
* Inspect the planar for leaked electrolyte, and the diskette drive boards more carefully still &mdash; that is where PS/2 capacitor damage actually shows up. See [[IBM PS/2 Model 30 Capacitor Replacement Guide]].


== PSU Voltage Checks ==
== Power supply checks ==


Power reaches the planar through '''two 6-pin connectors, P3 and P4'''. P3 is the one nearer the rear of the system.<ref name="tr30" />
The supply connects to the planar through two 6-pin connectors, P3 and P4; P3 is nearer the rear.<ref name="tr30" /><ref name="hmm" />


{| class="wikitable styled-table" style="width:100%; text-align:center;"
{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+'''Model 30 power supply connector pin assignments'''
|+'''P3 and P4 pin assignments'''
! Pin !! P3 !! P4
! Pin !! P3 !! P4
|-
|-
Line 134: Line 111:
| 2 || Ground || Ground
| 2 || Ground || Ground
|-
|-
| 3 || +12 V dc || &minus;5 V dc
| 3 || +12 V || −5 V
|-
|-
| 4 || &minus;12 V dc || +5 V dc
| 4 || −12 V || +5 V
|-
|-
| 5 || Ground || +5 V dc
| 5 || Ground || +5 V
|-
|-
| 6 || Ground || +5 V dc
| 6 || Ground || +5 V
|}
|}


Measure with the system powered on and running. IBM's service limits are given between specific pins, so put the meter's negative lead where the table says:
Measure with the system switched on and running, with the meter leads on the pins IBM specifies. The negative rails are measured with the leads reversed, so they read positive.<ref name="atpower">Louis Ohland, Tomáš Slavotínek ''et al.'', [https://www.ardent-tool.com/8530/Power.html "8525 / 8530 Power"], Ardent Tool of Capitalism. IBM's P3/P4 measurement limits for the Model 30 and 30-286, the minimum under-voltage sense levels, the Power Good reading of +3.5 to +5 V with the system running, and the procedure of removing adapters, cables and extra memory when Power Good is absent.</ref>


{| class="wikitable styled-table" style="width:100%; text-align:center;"
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''Model 30 and Model 30 286 &mdash; service measurement limits'''
|+'''Model 30 and Model 30 286 measurement limits'''
! Rail !! Negative lead !! Positive lead !! Minimum !! Maximum
! Rail !! − lead !! + lead !! Minimum !! Maximum
|-
|-
| +5 V || P3-5 || P4-4 || +4.8 V || +5.2 V
| +5 V || P3-5 || P4-4 || +4.8 V || +5.2 V
|-
|-
| &minus;5 V || P4-3 || P3-6 || +4.6 V || +5.5 V
| −5 V || P4-3 || P3-6 || +4.6 V || +5.5 V
|-
|-
| +12 V || P4-1 || P3-3 || +11.5 V || +12.6 V
| +12 V || P4-1 || P3-3 || +11.5 V || +12.6 V
|-
|-
| &minus;12 V || P3-4 || P4-2 || +10.8 V || +13.2 V
| −12 V || P3-4 || P4-2 || +10.8 V || +13.2 V
|}
|}


The negative rails are measured with the leads reversed, which is why they read as positive numbers.<ref name="atpower" />
The supply withholds Power Good unless every rail is above its minimum under-voltage sense level: +4.5 V on +5 V, −4.3 V on −5 V, +10.8 V on +12 V and −10.2 V on −12 V. After the machine has been off for five seconds or more, Power Good resets the system logic at switch-on and POST begins.<ref name="tr30" /><ref name="hmr286" />


The supply shuts itself down if a rail falls below its under-voltage sense level: +4.5 V on the +5 V rail, &minus;4.3 V on &minus;5 V, +10.8 V on +12 V and &minus;10.2 V on &minus;12 V.<ref name="tr30" /><ref name="atpower" /> A rail sitting just above its trip point will run on the bench and then drop the machine as soon as it is loaded.
Power Good at P3-1 should read +3.5 to +5 V with the system running. If it does not, remove all adapters, cables and extra memory and try again. If Power Good then appears, one of those items was shorting a rail; refit them one at a time to find it.<ref name="atpower" /> IBM's specification for the signal is 2.4 to 5.25 V active, 0.0 to 0.4 V inactive, with a turn-on delay of 100 to 500 ms.<ref name="tr30" />


'''Power Good''' should read '''+3.5 V to +5 V''' at P3-1 when the system is operating correctly. If it does not, strip out all adapters, cables and extra memory and try again; if Power Good comes up, one of those devices was shorting a rail, and you find it by reinstalling them one at a time.<ref name="atpower" /> IBM specifies the line as TTL-compatible, active at 2.4 to 5.25 V dc, inactive at 0.0 to 0.4 V dc, with a turn-on delay of not less than 100 ms and not more than 500 ms.<ref name="tr30" />
The supply FRU numbers are 61X8905 for the Model 30 and 27F4166 for the Model 30 286.<ref name="hmm" /> The 8086 Model 25 uses a different power connector from the 8086 Model 30, so its supply does not fit.<ref name="at8525planar" />


The Model 30 286's supply adds the 4-pin bus power connector; other than that connector the two supplies are interchangeable in the chassis.<ref name="dosdays30">"IBM PS/2 Model 30", DOS Days, https://www.dosdays.co.uk/computers/IBM%20PS2%20Model%2030/ibm_ps2_model_30.php. Source for the single-cable drive interface with no Molex connectors, the extra 4-pin bus power connector on the Model 30 286, the statement that the fixed-disk interface is neither ESDI nor standard MFM, the drive caddy, and the Sony 1.44 MB drive compatibility note including the "1.44MB" marking on the eject button.</ref> '''Do not fit a Model 25 supply''': the Model 25 8086 does not use the same power connector as the Model 30 8086.<ref name="at8525planar">Louis Ohland, William R. Walsh, Tomáš Slavotínek ''et al.'', "8525 Planar", Ardent Tool of Capitalism, https://www.ardent-tool.com/8525/Planar.html. Gives the Model 25 planar designator maps, the warning that the Model 25 8086 does not use the same power connector as the Model 30 8086, the riser card contents, and William Walsh's account of the surface-mount electrolytic failures on PS/2 diskette drives and of undocumented 1.44 MB support with Sony drives.</ref>
== Clock and battery ==


== Real-Time Clock and Battery ==
=== Model 30 ===


'''Both generations have a hardware real-time clock.''' IBM lists "Real-time clock with battery" among the 8086 Model 30's integrated system-board functions, with the clock at I/O addresses hex 00B0&ndash;00BF (command/status) and hex 00E0&ndash;00EF (counter/RAM).<ref name="tr30" />
The clock is a National Semiconductor MM58167AN at U16 with a 32.768 kHz crystal at Y4.<ref name="at8530planar" /> IBM lists it among the system board functions as "real-time clock with battery", at I/O addresses hex 00B0–00BF and 00E0–00EF.<ref name="tr30" />


=== Model 30 8086 ===
The cell is on the riser card (P/N 61X8864 or 61X8910), not the planar: a 3 V lithium Panasonic BR-2/3A soldered at B1.<ref name="at8530planar" /> IBM gave the cell no FRU number and replaced the whole riser. A direct replacement is a 2/3A (17 × 33.5 mm) cell with solder tabs, one pin on the negative tab and two on the positive: Panasonic BR-2/3A, Sanyo CR-2/3A or CR17335SE. A 3 V holder for two AA cells, or a BH2/3A holder, can be wired in instead.<ref name="atbatt">Ardent Tool of Capitalism, [https://www.ardent-tool.com/misc/batteries.html "PS/2 RTC/CMOS Batteries"], based on content by Bob Eager and Peter H. Wendt. Model 30 (8086): 3 V battery, soldered, no FRU; the through-hole cell "was to be replaced with the entire riser board"; BR-2/3A, CR-2/3A and CR17335SE equivalents and the tab arrangement; AA and BH2/3A holders. Model 30-286: Dallas module FRU 8509237 (DS1287), replaced by the DS12887, DS12887+, DS1287A, DS12887A or bq3287MT, not the DS12C887; reworking the module with an external cell.</ref>


The clock is a National Semiconductor '''MM58167AN at planar position U16''', timed by the '''Y4 32.768 kHz crystal'''.<ref name="at8530planar" />
IBM retain tip H067282 corrects the early 8530 Hardware Maintenance Service manual. On its system board map (page 0100-4) the bus adapter pins labelled "0" and "39" are really pins 1 and 40. Measure the battery voltage between pins 38 and 39, the second and third pins from the right-hand edge, and replace the bus adapter if it is below 2.5 V.<ref name="at8530planar" />


The cell that backs it is '''not on the planar'''. It is a '''3 V lithium Panasonic BR-2/3A soldered to the riser card at B1''' &mdash; riser P/N 61X8864 or 61X8910, which also carries the three 8-bit ISA slots and, apart from the battery, nothing else of consequence.<ref name="at8530planar" /> If the clock on an 8086 Model 30 will not hold time, '''pull the riser, not the planar'''. This catches people out: the riser is the last place most restorers look for a battery.
=== Model 30 286 ===


IBM's own service notice on the subject is worth knowing about, because the early manual got it wrong. Retain tip '''H067282''' records that early releases of the 8530 Hardware Maintenance Service manual, on system board map page 0100-4, label the bus adapter card's pins incorrectly: the pins printed as "0" and "39" are actually pins 1 and 40, and the voltage should be measured at '''pins 38 and 39''' &mdash; the second and third pins in from the right-hand edge. Replace the bus adapter card if the voltage between the correct pins is below '''2.5 V'''.<ref name="at8530planar" />
The clock and its CMOS RAM are in a Dallas DS1287 module with the lithium cell sealed inside, IBM FRU 8509237.<ref name="hmm" /><ref name="atbatt" /> The module plugs into a connector at ZM35. IBM's instructions are to remove it carefully without bending the pins or prying against the socket or board, and to fit it with the white dot towards the rear of the system unit.<ref name="hmr286" />


=== Model 30 286 ===
The DS1287 is obsolete. Replacements that work in a PS/2 are the DS12887, the lead-free DS12887+, the DS1287A and DS12887A, and the Benchmarq bq3287MT. The DS12C887 handles the century byte differently and does not work. The original module can also be reworked with an external cell.<ref name="atbatt" />


The clock is a '''Dallas DS1287 RTC/CMOS module at ZM35''', a 24-pin DIP with the lithium cell sealed inside it.<ref name="at8530planar286" /> When the cell runs down, POST reports:
=== Error codes and setup ===


* '''161''' &mdash; battery. IBM's FRU order for this code is battery, then complex, then system board, then bus adapter.
IBM's FRU order and actions for the clock and configuration codes:<ref name="hmm" />
* '''162''' &mdash; configuration changed; check that all devices are powered on and that the configuration has not been altered, then run Automatic Configuration. If that does not clear it, suspect the battery.
* '''163''' &mdash; date and time error; set the date and time.
* '''167''' &mdash; clock not running correctly.
* '''168''' &mdash; real-time clock error; run Advanced Diagnostics. This is not always a hardware failure.<ref name="aterr">"PS/2 Error Codes" and the error code listings, Ardent Tool of Capitalism, https://www.ardent-tool.com/trouble/ps2error.html. Error codes 160&ndash;199 (https://www.ardent-tool.com/trouble/error_02.html) and 300&ndash;999 (https://www.ardent-tool.com/trouble/error_04.html) give the 161/162/163/167/168 battery and clock cluster, the 301&ndash;307 keyboard cluster, 305 "keyboard voltage error" with the keyboard port fuse as the first FRU, and the 601&ndash;668 diskette cluster including 604 "unsupported drive or cable" and 662 "wrong drive type installed". The main page gives the dead-system isolation procedure.</ref>


Replacement is by desoldering the 24-pin DS1287 and fitting a fresh DS12887+ or equivalent; some restorers instead cut into the original module's case to reach the cell and fit an external holder. IBM's own caution on the 161 code is worth repeating: '''the lithium cell presents a fire, explosion and burn risk''' &mdash; do not heat, crush, short or recharge it.<ref name="aterr" /> See [[Battery Refurbishment]] and [[Battery Explosion, Capacitor or Corrosion Damage]].
{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Codes 161–168 (IBM ''PS/2 Hardware Maintenance Manual'')'''
! Code !! Meaning !! IBM action or FRU order
|-
| 161 || Battery || Battery, system board, bus adapter
|-
| 162 || Configuration || Check all devices are powered on; if the configuration has changed, run Automatic Configuration. Then any device, battery
|-
| 163 || Date and time || Set the date and time
|-
| 165, 167 || Configuration, date or time not set || Set configuration and features, then system board
|-
| 168 || Real-time clock || Run Advanced Diagnostics; not always a hardware fault
|}


After either job, boot the Reference or Starter Diskette and run Set Configuration to re-enter memory size, drive type and the date and time.
IBM's caution with code 161 is that the lithium battery presents a fire, explosion or severe burn risk. A weak battery loses all the setup information; if only part of it is lost, the battery is probably not the cause.<ref name="aterr">[https://www.ardent-tool.com/trouble/ps2error.html "PS/2 Error Codes"], Ardent Tool of Capitalism, with the code tables for [https://www.ardent-tool.com/trouble/error_02.html 160–199] and [https://www.ardent-tool.com/trouble/error_04.html 300–999]. The warm-boot warning, the battery note, 305 (keyboard voltage error; keyboard port fuse, keyboard cable, system board; "If no fuse in system replace system board"), 604 (unsupported drive or cable, drive must be media sense type) and 662 and 663 (wrong drive type, wrong media type; information only).</ref> See [[Battery Refurbishment]] and [[Battery Explosion, Capacitor or Corrosion Damage]].
 
After replacing the battery or module, start the Starter Diskette and let Automatic Configuration run, or restore a customised configuration from the backup copy of the Starter Diskette. Then set the date and time.<ref name="hmr286" />


=== Power-on password ===
=== Power-on password ===


If the power-on password on a Model 30 286 is forgotten, move the '''J13''' jumper on the planar to its other position: if it covers the first and second pins, move it to the second and third, and vice versa. Leave it where you moved it until the next time it needs resetting.<ref name="gto30286" /><ref name="at8530planar286" />
To clear a forgotten power-on password on a Model 30 286, find the J13 jumper on the system board. If it covers the first and second pins, move it to the second and third; if it covers the second and third, move it to the first and second. Leave it in the new position until the password next needs resetting.<ref name="gto30286" /><ref name="hmr286" />


== Connector Care ==
== Connector care ==


* '''Keyboard and pointing device (Mini-DIN-6)''': these are two physically identical sockets with different functions &mdash; J1 is the mouse, J2 the keyboard.<ref name="at8530planar" /> They are not interchangeable. The plastic key aligns the plug; do not force it.
* The keyboard and pointing-device sockets use the same interface logic. On the Model 30 either device can plug into either socket.<ref name="tr30" /> On the Model 30 286 the keyboard socket is marked "1" and the pointing device "2".<ref name="hmr286" />
* '''Keyboard and mouse fuses''': F1 and F2 on the planar protect the +5 V feed to the two ports, combined into a single F1 on the later alternative Greenock board.<ref name="at8530planar" /> A '''305''' at POST is a keyboard voltage error, and IBM's first FRU for it is the keyboard port fuse.<ref name="aterr" />
* The ports are fused on the planar. Code 305 is a keyboard voltage error, and IBM's first FRU is the keyboard port fuse, then the keyboard cable, then the system board.<ref name="aterr" /><ref name="at8530planar" /><ref name="at8530planar286" />
* '''Parallel port''' (DB-25) and '''serial port''' (DB-25 on the 8086 planar) are conventional.<ref name="tr30" /><ref name="at8530planar" />
* The parallel and serial ports are 25-pin D connectors.<ref name="at8530planar" />


== Single-Cable Drive Interface ==
== Drive interface ==


The PS/2 drive interface carries power and data in one ribbon cable from the planar to the drive; there are no Molex connectors anywhere in the machine.<ref name="dosdays30" /> IBM's published pin assignments show exactly where the power sits:
Each drive takes power and signals through one cable from the planar; there are no separate drive power connectors.<ref name="dosdays30">[https://www.dosdays.co.uk/computers/IBM%20PS2%20Model%2030/ibm_ps2_model_30.php "IBM PS/2 Model 30"], DOS Days. The drive fitting with no Molex connectors, the Model 30 fixed-disk interface being neither ESDI nor standard MFM, the drive caddy, and the Sony 1.44 MB drive that works in the 8086 machine.</ref> On the Model 30 planar IBM gives:


* '''Diskette (J12, 40-pin)''': pin 38 is +5 V dc and pin 40 is +12 V dc; odd-numbered pins 1 to 35 are signal ground.<ref name="tr30" />
* diskette connector J12 (40 pins): pin 38 +5 V, pin 40 +12 V, all odd pins and pin 36 ground;<ref name="tr30" />
* '''Fixed disk (J11, 44-pin)''': pins 30 and 32 are +5 V dc, pins 40, 42 and 44 are +12 V dc.<ref name="tr30" />
* fixed-disk connector J11 (44 pins): pins 30 and 32 +5 V, pins 40, 42 and 44 +12 V.<ref name="tr30" />


Care points:
Because the supply rails share the connector with the signal lines, check that each cable is aligned and fully seated before switching on. On the Model 30 286's 1/3-height diskette cable, IBM notes that pins 35 to 40 at the system-board end are not used.<ref name="hmr286" />


* Align the cable's stripe to pin 1 at both ends.
== Diskette drives ==
* Because the supply rails ride on the same connector as the data lines, a mis-inserted or offset cable puts +12 V onto signal pins. Check the alignment twice before powering up.
* The drives have no dust shutter, so dust reaches the heads. Clean periodically.<ref name="at8525planar" />


== Diskette Drive Maintenance ==
* The 8086 machines shipped with 720 KB drives (FRU 96F7678). The Model 30 286 uses 1.44 MB drives: FRU 72X8523 (half height) or 64F0162 (one-third height).<ref name="hmm" />
* A 1.44 MB drive has "1.44" on its eject button. It reads and writes both 1 MB (720 KB) and 2 MB (1.44 MB) diskettes; a 720 KB drive cannot use 2 MB diskettes.<ref name="hmr286" />
* The 8086 Model 30 has undocumented high-density support. Sony drives are the ones likely to work; other makes are seen as low density or not at all, and later planars accept more drives.<ref name="at8525planar" /><ref name="dosdays30" />
* Code 604 means an unsupported drive or cable (the drive must be a media-sense type). Codes 662 and 663 report the wrong drive type or the wrong media and are information only.<ref name="aterr" />
* The drives are direct drive with no belt; the Mitsubishi MF355C turns the spindle directly at 300 rpm.<ref name="mf355c">Mitsubishi Electric, ''3.5 inch Flexible Disk Drive Standard Specifications, MF355C'', UGD-0527A, February 1987. Hosted on this wiki as [[:File:Mitsubishi MF355C 3.5 inch Diskette Drive Specifications (UGD-0527A, Feb 1987).pdf]]. Section 3: brushless DC direct-drive spindle motor at 300 rpm.</ref> The common faults are dirt on the Mitsubishi head actuator spindle, a detached head-damper pad on ALPS drives, and leaking capacitors on the drive board.<ref name="atcommon60" /> See [[IBM PS/2 Model 30 Capacitor Replacement Guide]] and [[Floppy Drive Repair]].


* The 8086 machines shipped with 720 KB drives and the 286 machines with 1.44 MB.<ref name="ann187048" /><ref name="ann189035" /> You can tell which you have from the blue eject button: a high-density drive has "1.44MB" moulded into it.<ref name="dosdays30" />
== Fixed disk ==
* Use DSDD media in a 720 KB drive. A '''662''' at POST means the wrong drive type is installed and a '''663''' means the wrong media type is in the drive; '''604''' means an unsupported drive or cable, the drive having to be a media-sense type.<ref name="aterr" />
* IBM never shipped the 8086 Model 30 with a high-density drive, but the machine does have undocumented 1.44 MB support. Sony-manufactured drives are the ones likely to work; other makes are recognised only as low-density, or not at all. Which planar you have also matters &mdash; the later boards are more tolerant.<ref name="at8525planar" /><ref name="dosdays30" />
* '''These drives have no belt.''' The Mitsubishi MF355C family rotates the disk with a DC brushless direct-drive motor coupled straight to the spindle at 300 rpm.<ref name="mf355c">Mitsubishi Electric, ''3.5 inch Flexible Disk Drive Standard Specifications, MF355C'', document UGD-0527A, February 1987. [[:File:Mitsubishi MF355C 3.5 inch Diskette Drive Specifications (UGD-0527A, Feb 1987).pdf]]. Section 3 states that the disk rotation mechanism uses a DC brushless direct-drive motor to rotate the spindle directly at 300 rpm.</ref> A drive that will not spin or spins slowly needs its board and motor examined, not a belt.
* The real wear item is the surface-mount electrolytics on the drive logic board, which leak and corrode the board underneath. See [[IBM PS/2 Model 30 Capacitor Replacement Guide]] and [[Floppy Drive Repair]].


== Fixed Disk Maintenance ==
The Model 30's fixed-disk connector is a dedicated I/O channel, not an ST-506, ESDI or IDE interface. It carries I/O channel signals with IRQ 5 and DMA channel 3, a card-select decoded at hex 032x, a "disk installed" line and three address lines that select registers inside the controller, which is part of the drive.<ref name="tr30" /><ref name="ann187048" /> Only IBM's drives for this interface work, and the drive sits in a caddy.<ref name="dosdays30" /> IBM's parts lists give 20 MB drives FRU 6128285 and 61X8929, a 30 MB drive 6128279 and, for the 286, a 45 MB drive 92F0016.<ref name="hmm" />


The Model 30's fixed-disk interface is '''not ST-506, not ESDI and not IDE'''. IBM describes J11 as a dedicated I/O channel: it carries the ordinary I/O channel signals needed for fixed-disk operation &mdash; I/O read and write, reset, the data lines, I/O CH RDY, IRQ5 and the DMA request and acknowledge lines &mdash; plus a &minus;DISK CS card-select decoded at hex 032x, a &minus;DISK Installed line and address lines A0 to A2 to select a register inside the controller.<ref name="tr30" /> '''The controller is on the drive, not on the planar''': IBM's own announcement describes the 8530-021 as shipping with "one 20MB fixed disk with integrated controller".<ref name="ann187048" /><ref name="dosdays30" />
* Before removing a fixed disk from a Model 30 286, IBM says to park the heads with the Advanced Diagnostics diskette.<ref name="hmr286" />
* A drive that will not spin up after long storage may have stiction, the heads stuck to the platters. Peter Wendt's options are power cycling, or unplugging the unit and rotating it sharply a few times; he warns never to lift and drop the front of the case. Copy the data off at once if it starts.<ref name="atstiction">[https://www.ardent-tool.com/trouble/Problems.html "Known Problems – Experience, RETAIN Tips, ECAs"], Ardent Tool of Capitalism. Peter Wendt on hard-disk stiction and ways to free a stuck drive.</ref>
* An XT-IDE card on the ISA bus is the storage upgrade Ardent Tool suggests for the related 8086 Model 25, and it bypasses the planar interface.<ref name="at8525planar" />


In practice:
IBM retain tip H007157 says that fixed-disk operation on the 8530-001 and -021 depends on the right combination of system board, fixed disk and Advanced Diagnostics version, and that formatting with the wrong version causes fixed-disk errors:<ref name="at8530planar" />
 
* Only the original IBM drive assemblies are recognised, and the setup diskette offers no other drive types.<ref name="dosdays30" />
* Those drives are failure-prone. If one will not spin up, suspect head stiction; rotating the drive body by hand with the power off sometimes frees it, but treat that as a way to get the data off, not as a repair.
* Practical replacements are an XT-IDE card on the ISA bus, an SD-based emulator, or an MFM emulator &mdash; all of which sidestep the planar interface entirely.
* The drive sits in a metal caddy held by the same plastic captive push-pin mechanism as everything else.<ref name="dosdays30" />
 
IBM issued a service notice about drive and board combinations on these machines. Retain tip '''H007157''' records that successful fixed-disk operation on the 8530-001 and -021 depends on matching the system board, the drive and the version of Advanced Diagnostics used to format it &mdash; and that formatting with the wrong version of the diagnostics causes fixed-disk errors:<ref name="at8530planar" />


{| class="wikitable styled-table" style="width:100%; text-align:center;"
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+'''IBM retain tip H007157 &mdash; required FRU combinations'''
|+'''IBM retain tip H007157, required combinations'''
! Machine type !! System board !! Fixed disk !! Advanced Diagnostics
! Machine !! System board !! Fixed disk !! Advanced Diagnostics
|-
|-
| 8530-021 below serial 2500000 || P/N 61X8907 || P/N 61X8929 || 8530, any version
| 8530-021 below serial 2500000 || 61X8907 || 61X8929 || 8530, any version
|-
|-
| 8530-021 above serial 2500000 || P/N 33F8474 || P/N 6128285 || 8530, version 1.05
| 8530-021 above serial 2500000 || 33F8474 || 6128285 || 8530, version 1.05
|-
|-
| 8530-001, all || P/N 33F8474 || P/N 6128285 or 6128279 || 8530, version 1.05
| 8530-001, all || 33F8474 || 6128285 or 6128279 || 8530, version 1.05
|-
|-
| 8530-E21 only || P/N 27F4069 || P/N 6128285 || 8530-286, version 1.02
| 8530-E21 only || 27F4069 || 6128285 || 8530-286, version 1.02
|-
|-
| 8530-E31 and E01 || P/N 34F0046 || P/N 6128285 or 6128279 || 8530-286, version 1.02
| 8530-E31 and E01 || 34F0046 || 6128285 or 6128279 || 8530-286, version 1.02
|}
|}


Fixed disks P/N 6128285 and 6128279 must '''not''' be installed in any 8530-021 below serial number 2500000.<ref name="at8530planar" />
Drives 6128285 and 6128279 must not be fitted to an 8530-021 below serial number 2500000. Version 1.05 of the 8530 Advanced Diagnostics was IBM publication S15F-2153.<ref name="at8530planar" />
 
== Known IBM Service Notices ==


Three more IBM notices are worth checking before chasing a fault on an 8530.
== IBM service notices ==


* '''H043664 &mdash; cursor keys and 501 POST errors.''' On a limited number of 8530-001 and -021 machines, the cursor keys produce unexpected characters on the display, and a '''501''' appears when two or more option cards are fitted. Inspect the modules at planar positions '''U9''' (next to the coprocessor socket) and '''U15''' (next to the speaker). U9 P/N 72X8203 and U15 P/N 61X8965 are suspect if they are marked "IBM" but '''do not carry the word "Japan"'''; good parts have it. IBM's fix was to replace the system board with FRU P/N 64F3453. Machines with serial numbers above 55-00HV000 already have the new board.<ref name="at8530planar" />
IBM retain tip H043664 covers some 8530-001 and -021 machines on which the cursor keys put unexpected characters on the screen and a 501 appears with two or more option cards fitted, such as the 3270 and Token-Ring adapters. Advanced Diagnostics may not detect it. Check the modules at U9 (next to the coprocessor socket, P/N 72X8203) and U15 (next to the speaker, P/N 61X8965): good ones have "Japan" printed on them. IBM's fix was system board FRU 64F3453; machines with serial numbers above 55-00HV000 already have it.<ref name="at8530planar" />
* '''H094152 &mdash; 8515 and 8516 displays.''' The 8086 Model 30 (models 001, 002 and 021) does '''not''' support PS/2 8515 or 8516 displays; attaching one gives compressed, distorted video. It does support the 8503, 8504, 8507, 8512, 8513 and 8514. The 286 machines (E01, E21, E31, E41) support the 8503, 8504, 8512, 8513, 8514, 8515 and 8516.<ref name="at8530planar" />
* '''H036143 &mdash; 8602 with a 4717 printer.''' On a Model 30 286 shipped after 1 August 1989, attaching a 4717 directly gives an 8602 POST error and the printer does not work, because a planar change grounded pin 2 of the pointing-device port. IBM's fix was an interposer cable, P/N 31F6759.<ref name="at8530planar286" />


== Things That Are Not Faults ==
Retain tip H094152 states that the 8086 models 001, 002 and 021 do not support the 8515 or 8516 and show compressed, distorted video on them. They support the 8503, 8504, 8507, 8512, 8513 and 8514. The 286 models support the 8503, 8504, 8512, 8513, 8514, 8515 and 8516.<ref name="at8530planar" />


* An 8086 Model 30 will not drive an 8515 or 8516 display properly. That is a documented limitation, not a fault.<ref name="at8530planar" />
Retain tip H036143 covers Model 30 286 machines shipped after 1 August 1989, on which a 4717 printer attached directly gives an 8602 error and does not work, because a planar change grounded pin 2 of the pointing-device port. IBM supplied interposer cable P/N 31F6759 (RPQ S82021).<ref name="at8530planar286" />
* A '''162''' after you have added or removed a device is the machine noticing the change. Run Set Configuration before suspecting the battery.<ref name="aterr" />
* Soft-booting the Reference Diskette with Ctrl-Alt-Del can throw false errors and a false indication that a power-on password is already set. Cold boot with the diskette in the drive.<ref name="aterr" />
* A '''663''' means the diskette in the drive is the wrong media type for that drive. It is information, not a failure.<ref name="aterr" />


== Capacitor Health ==
== Things that are not faults ==


Tantalum beads on the planar can fail short and stop the supply from coming up; aluminium electrolytics on the diskette drive boards leak and corrode. Full procedures, including what is and is not documented about this machine's capacitors, are in [[IBM PS/2 Model 30 Capacitor Replacement Guide]].
* Distorted video on an 8515 or 8516 connected to an 8086 Model 30 (H094152 above).
* A 162 after a device has been added or removed. Run Automatic Configuration before suspecting the battery.<ref name="hmm" />
* False errors, or a false power-on password prompt, after warm-booting the Starter Diskette. Switch on with the diskette already in the drive.<ref name="aterr" />
* Codes 662 and 663, which report the wrong drive or media type.<ref name="aterr" />


== Recommended Tools ==
== Recommended tools ==


* Philips screwdriver and an anti-static strap.
* Screwdriver and anti-static wrist strap.
* Plastic spudger for the captive push-pin fittings.
* Digital multimeter.
* Digital multimeter.
* IPA and foam swabs for connector cleaning.
* Isopropyl alcohol and foam swabs.
* Fine-tipped soldering iron and solder wick for RTC and capacitor work.
* Soldering iron and solder wick for riser-battery and capacitor work.
* A replacement RTC module for a Model 30 286, or a fresh BR-2/3A-format 3 V lithium cell for an 8086 riser.
* A 2/3A 3 V lithium cell with tabs (Model 30) or a DS12887-type module (Model 30 286).
* A written copy of the model-specific Reference or Starter Diskette.
* Copies of the Starter Diskette and Advanced Diagnostics diskette for the model.


See also [[Recommended Tools]].
See also [[Recommended Tools]].


== Related Pages ==
== Related pages ==


* [[IBM PS/2 Model 30]]
* [[IBM PS/2 Model 30]]
* [[IBM PS/2 Model 30 Troubleshooting Guide]]
* [[IBM PS/2 Model 30 Troubleshooting Guide]]
* [[IBM PS/2 Model 30 Capacitor Replacement Guide]]
* [[IBM PS/2 Model 30 Capacitor Replacement Guide]]
* [[IBM PS/2 Model 25 Maintenance Guide]] &mdash; the all-in-one sister machine
* [[IBM PS/2 Model 25 Maintenance Guide]]
* [[Hard Drive Maintenance and Repair]]
* [[Hard Drive Maintenance and Repair]]
* [[Floppy Drive Repair]]
* [[Floppy Drive Repair]]

Revision as of 20:41, 30 September 2026

An IBM PS/2 Model 30 286 (8530-E series). (Image: DigitalIceAge, CC BY 4.0, via Wikimedia Commons)

Routine maintenance on the IBM PS/2 Model 30 (machine type 8530) covers two machines: the original 8086 Model 30 (8530-001, -002, -021) and the Model 30 286 (8530-E01 to E41). Both are desktop system units with no built-in display, so the work is on the planar, the riser card, the power supply and the drives.

Safety

The power supply rectifies the mains, and its reservoir capacitor holds about 170 V on 120 V mains or about 325 V on 230 V mains after the plug is pulled. Before working inside the supply, unplug it, discharge that capacitor through a resistor and confirm with a meter that it has fallen to a few volts.

On a Model 30 286, set the voltage switch on the rear to 100–125 V or 200–240 V before plugging in the power cord.[1] The 8086 Model 30 supply accepts 120 V or 220/240 V without a switch.[2]

There is no CRT in the system unit. For a PS/2 display, see CRT Discharge Procedure.

Identifying your model

The machine type and submodel are on the rear label, for example "Type 8530-E21".

Model 30 and Model 30 286
Model 30 Model 30 286
Submodels 001, 002, 021 E01, E21, E31, E41 (E0R, E2R with a 50-key keyboard)
Processor 8086-2 at 8 MHz, U10 80286 at 10 MHz, ZM36
Video MCGA VGA
Clock MM58167AN at U16; 3 V cell soldered to the riser DS1287 clock module in a socket at ZM35
Diskette drive 720 KB 1.44 MB, "1.44" on the eject button
Power supply 70 W, no voltage switch 90 W, voltage switch on the rear

Sources: IBM's announcement letters and Hardware Maintenance Manual,[3][4] the HMR[1] and the planar maps.[5][6]

Planar layout

The 8086 planar was built as P/N 61X8823 and in two later Greenock versions, P/N 33F4888 and FRU 33F8474. The reference designators are largely the same on all three and on the 8086 Model 25.[5]

Model 30 (8086) planar
Designator Device
J1, J2 Mouse and keyboard connectors
J3 Parallel port
J4 Video connector (HD-15)
J5 Serial port (DB-25)
J6 Riser slot
J7, J9 Power connectors
J10 Two-pin keylock header
J11 44-pin fixed-disk connector
J12 40-pin diskette connector
J13 Dual 30-pin memory socket
F1, F2 Probably the mouse and keyboard fuses (F2 absent on the second Greenock board)
U10 Intel 8086-2
U13 8087 socket
U16 MM58167AN real-time clock
U17, U20 ROM BIOS
SP1 Speaker
Y4 32.768 kHz clock crystal

On the 286 planar, IBM's HMR locates J3 parallel, J5 serial, J6 bus adapter (riser), J1 pointing device, J2 keyboard, J9 and J10 memory packs, J11 fixed disk, J7 and J14 power, J4 display, J13 password override, ZM36 processor, ZM35 clock module, ZM1 coprocessor and J12 diskette.[1]

Opening the system unit

Tools: a screwdriver and an anti-static wrist strap. IBM's steps for the Model 30 286:[7]

  1. Turn off the system unit and every external device.
  2. Unplug the system unit's power cord, then the cords of any external devices.
  3. Remove all cables from the rear.
  4. If there is a cover lock, unlock it and remove the key.
  5. Loosen the two cover screws and remove the cover.
A Model 30 286 with the cover off. (Image: DigitalIceAge, CC BY 4.0, via Wikimedia Commons)

IBM's removal order for the system board is adapters, bus adapter (riser), memory packs and coprocessor, then all cables. The power supply comes out after the cover, the rear cover and the bus-adapter support.[1]

Cleaning

  • Brush and blow dust out of the planar, riser, drives and supply vents with low-pressure air. Hold any fan still while doing so.
  • Clean the keyboard and mouse sockets and the DB-25 connectors with contact cleaner on a foam swab.
  • Check the planar for leaked electrolyte, and the diskette drive board more closely: PS/2 drives have no dust shutter and collect dirt, and their surface-mount electrolytics leak.[8][9] See IBM PS/2 Model 30 Capacitor Replacement Guide.

Power supply checks

The supply connects to the planar through two 6-pin connectors, P3 and P4; P3 is nearer the rear.[2][4]

P3 and P4 pin assignments
Pin P3 P4
1 Power Good Ground
2 Ground Ground
3 +12 V −5 V
4 −12 V +5 V
5 Ground +5 V
6 Ground +5 V

Measure with the system switched on and running, with the meter leads on the pins IBM specifies. The negative rails are measured with the leads reversed, so they read positive.[10]

Model 30 and Model 30 286 measurement limits
Rail − lead + lead Minimum Maximum
+5 V P3-5 P4-4 +4.8 V +5.2 V
−5 V P4-3 P3-6 +4.6 V +5.5 V
+12 V P4-1 P3-3 +11.5 V +12.6 V
−12 V P3-4 P4-2 +10.8 V +13.2 V

The supply withholds Power Good unless every rail is above its minimum under-voltage sense level: +4.5 V on +5 V, −4.3 V on −5 V, +10.8 V on +12 V and −10.2 V on −12 V. After the machine has been off for five seconds or more, Power Good resets the system logic at switch-on and POST begins.[2][1]

Power Good at P3-1 should read +3.5 to +5 V with the system running. If it does not, remove all adapters, cables and extra memory and try again. If Power Good then appears, one of those items was shorting a rail; refit them one at a time to find it.[10] IBM's specification for the signal is 2.4 to 5.25 V active, 0.0 to 0.4 V inactive, with a turn-on delay of 100 to 500 ms.[2]

The supply FRU numbers are 61X8905 for the Model 30 and 27F4166 for the Model 30 286.[4] The 8086 Model 25 uses a different power connector from the 8086 Model 30, so its supply does not fit.[9]

Clock and battery

Model 30

The clock is a National Semiconductor MM58167AN at U16 with a 32.768 kHz crystal at Y4.[5] IBM lists it among the system board functions as "real-time clock with battery", at I/O addresses hex 00B0–00BF and 00E0–00EF.[2]

The cell is on the riser card (P/N 61X8864 or 61X8910), not the planar: a 3 V lithium Panasonic BR-2/3A soldered at B1.[5] IBM gave the cell no FRU number and replaced the whole riser. A direct replacement is a 2/3A (17 × 33.5 mm) cell with solder tabs, one pin on the negative tab and two on the positive: Panasonic BR-2/3A, Sanyo CR-2/3A or CR17335SE. A 3 V holder for two AA cells, or a BH2/3A holder, can be wired in instead.[11]

IBM retain tip H067282 corrects the early 8530 Hardware Maintenance Service manual. On its system board map (page 0100-4) the bus adapter pins labelled "0" and "39" are really pins 1 and 40. Measure the battery voltage between pins 38 and 39, the second and third pins from the right-hand edge, and replace the bus adapter if it is below 2.5 V.[5]

Model 30 286

The clock and its CMOS RAM are in a Dallas DS1287 module with the lithium cell sealed inside, IBM FRU 8509237.[4][11] The module plugs into a connector at ZM35. IBM's instructions are to remove it carefully without bending the pins or prying against the socket or board, and to fit it with the white dot towards the rear of the system unit.[1]

The DS1287 is obsolete. Replacements that work in a PS/2 are the DS12887, the lead-free DS12887+, the DS1287A and DS12887A, and the Benchmarq bq3287MT. The DS12C887 handles the century byte differently and does not work. The original module can also be reworked with an external cell.[11]

Error codes and setup

IBM's FRU order and actions for the clock and configuration codes:[4]

Codes 161–168 (IBM PS/2 Hardware Maintenance Manual)
Code Meaning IBM action or FRU order
161 Battery Battery, system board, bus adapter
162 Configuration Check all devices are powered on; if the configuration has changed, run Automatic Configuration. Then any device, battery
163 Date and time Set the date and time
165, 167 Configuration, date or time not set Set configuration and features, then system board
168 Real-time clock Run Advanced Diagnostics; not always a hardware fault

IBM's caution with code 161 is that the lithium battery presents a fire, explosion or severe burn risk. A weak battery loses all the setup information; if only part of it is lost, the battery is probably not the cause.[12] See Battery Refurbishment and Battery Explosion, Capacitor or Corrosion Damage.

After replacing the battery or module, start the Starter Diskette and let Automatic Configuration run, or restore a customised configuration from the backup copy of the Starter Diskette. Then set the date and time.[1]

Power-on password

To clear a forgotten power-on password on a Model 30 286, find the J13 jumper on the system board. If it covers the first and second pins, move it to the second and third; if it covers the second and third, move it to the first and second. Leave it in the new position until the password next needs resetting.[7][1]

Connector care

  • The keyboard and pointing-device sockets use the same interface logic. On the Model 30 either device can plug into either socket.[2] On the Model 30 286 the keyboard socket is marked "1" and the pointing device "2".[1]
  • The ports are fused on the planar. Code 305 is a keyboard voltage error, and IBM's first FRU is the keyboard port fuse, then the keyboard cable, then the system board.[12][5][6]
  • The parallel and serial ports are 25-pin D connectors.[5]

Drive interface

Each drive takes power and signals through one cable from the planar; there are no separate drive power connectors.[13] On the Model 30 planar IBM gives:

  • diskette connector J12 (40 pins): pin 38 +5 V, pin 40 +12 V, all odd pins and pin 36 ground;[2]
  • fixed-disk connector J11 (44 pins): pins 30 and 32 +5 V, pins 40, 42 and 44 +12 V.[2]

Because the supply rails share the connector with the signal lines, check that each cable is aligned and fully seated before switching on. On the Model 30 286's 1/3-height diskette cable, IBM notes that pins 35 to 40 at the system-board end are not used.[1]

Diskette drives

  • The 8086 machines shipped with 720 KB drives (FRU 96F7678). The Model 30 286 uses 1.44 MB drives: FRU 72X8523 (half height) or 64F0162 (one-third height).[4]
  • A 1.44 MB drive has "1.44" on its eject button. It reads and writes both 1 MB (720 KB) and 2 MB (1.44 MB) diskettes; a 720 KB drive cannot use 2 MB diskettes.[1]
  • The 8086 Model 30 has undocumented high-density support. Sony drives are the ones likely to work; other makes are seen as low density or not at all, and later planars accept more drives.[9][13]
  • Code 604 means an unsupported drive or cable (the drive must be a media-sense type). Codes 662 and 663 report the wrong drive type or the wrong media and are information only.[12]
  • The drives are direct drive with no belt; the Mitsubishi MF355C turns the spindle directly at 300 rpm.[14] The common faults are dirt on the Mitsubishi head actuator spindle, a detached head-damper pad on ALPS drives, and leaking capacitors on the drive board.[8] See IBM PS/2 Model 30 Capacitor Replacement Guide and Floppy Drive Repair.

Fixed disk

The Model 30's fixed-disk connector is a dedicated I/O channel, not an ST-506, ESDI or IDE interface. It carries I/O channel signals with IRQ 5 and DMA channel 3, a card-select decoded at hex 032x, a "disk installed" line and three address lines that select registers inside the controller, which is part of the drive.[2][3] Only IBM's drives for this interface work, and the drive sits in a caddy.[13] IBM's parts lists give 20 MB drives FRU 6128285 and 61X8929, a 30 MB drive 6128279 and, for the 286, a 45 MB drive 92F0016.[4]

  • Before removing a fixed disk from a Model 30 286, IBM says to park the heads with the Advanced Diagnostics diskette.[1]
  • A drive that will not spin up after long storage may have stiction, the heads stuck to the platters. Peter Wendt's options are power cycling, or unplugging the unit and rotating it sharply a few times; he warns never to lift and drop the front of the case. Copy the data off at once if it starts.[15]
  • An XT-IDE card on the ISA bus is the storage upgrade Ardent Tool suggests for the related 8086 Model 25, and it bypasses the planar interface.[9]

IBM retain tip H007157 says that fixed-disk operation on the 8530-001 and -021 depends on the right combination of system board, fixed disk and Advanced Diagnostics version, and that formatting with the wrong version causes fixed-disk errors:[5]

IBM retain tip H007157, required combinations
Machine System board Fixed disk Advanced Diagnostics
8530-021 below serial 2500000 61X8907 61X8929 8530, any version
8530-021 above serial 2500000 33F8474 6128285 8530, version 1.05
8530-001, all 33F8474 6128285 or 6128279 8530, version 1.05
8530-E21 only 27F4069 6128285 8530-286, version 1.02
8530-E31 and E01 34F0046 6128285 or 6128279 8530-286, version 1.02

Drives 6128285 and 6128279 must not be fitted to an 8530-021 below serial number 2500000. Version 1.05 of the 8530 Advanced Diagnostics was IBM publication S15F-2153.[5]

IBM service notices

IBM retain tip H043664 covers some 8530-001 and -021 machines on which the cursor keys put unexpected characters on the screen and a 501 appears with two or more option cards fitted, such as the 3270 and Token-Ring adapters. Advanced Diagnostics may not detect it. Check the modules at U9 (next to the coprocessor socket, P/N 72X8203) and U15 (next to the speaker, P/N 61X8965): good ones have "Japan" printed on them. IBM's fix was system board FRU 64F3453; machines with serial numbers above 55-00HV000 already have it.[5]

Retain tip H094152 states that the 8086 models 001, 002 and 021 do not support the 8515 or 8516 and show compressed, distorted video on them. They support the 8503, 8504, 8507, 8512, 8513 and 8514. The 286 models support the 8503, 8504, 8512, 8513, 8514, 8515 and 8516.[5]

Retain tip H036143 covers Model 30 286 machines shipped after 1 August 1989, on which a 4717 printer attached directly gives an 8602 error and does not work, because a planar change grounded pin 2 of the pointing-device port. IBM supplied interposer cable P/N 31F6759 (RPQ S82021).[6]

Things that are not faults

  • Distorted video on an 8515 or 8516 connected to an 8086 Model 30 (H094152 above).
  • A 162 after a device has been added or removed. Run Automatic Configuration before suspecting the battery.[4]
  • False errors, or a false power-on password prompt, after warm-booting the Starter Diskette. Switch on with the diskette already in the drive.[12]
  • Codes 662 and 663, which report the wrong drive or media type.[12]
  • Screwdriver and anti-static wrist strap.
  • Digital multimeter.
  • Isopropyl alcohol and foam swabs.
  • Soldering iron and solder wick for riser-battery and capacitor work.
  • A 2/3A 3 V lithium cell with tabs (Model 30) or a DS12887-type module (Model 30 286).
  • Copies of the Starter Diskette and Advanced Diagnostics diskette for the model.

See also Recommended Tools.

References

  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 IBM, IBM PS/2 Model 30 286 Hardware Maintenance Reference, S64F-3988-00, March 1990. Hosted on this wiki as IBM PS2 Model 30 286 Hardware Maintenance Reference (PDF). Sections 1.1.2 (power-on password, J13), 1.2.2 (CMOS RAM and battery), 1.2.6 (keyboard and pointing-device connectors), 2.2 (diskette drive identification and media compatibility), 3.1 (power supply switch and under-voltage sense levels), 3.2 (POST), 6.3 (park the heads before removing a fixed disk), 6.14 (1070 clock module), 7.4 (system board locations), 7.6 (1/3-height diskette cable).
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 IBM, IBM Personal System/2 Model 30 Technical Reference, January 1987. Hosted on this wiki as IBM PS2 Model 30 Technical Reference (January 1987) (PDF). Keyboard and pointing device controller, p. 1-9; interrupt listing, Figure 1-9; I/O address map, Figure 1-12; diskette drive connector, Figure 1-97, p. 1-105; fixed disk connector, pp. 1-106 and 1-107; Section 3, "Power Supply", pp. 3-3 to 3-6 (input, outputs, sense levels, power-good signal, P3 and P4 pin assignments).
  3. ↑ 3.0 3.1 IBM Announcement Letter 187-048, IBM Personal System/2 Model 30, 2 April 1987, text at ardent-tool.com. Models 002 and 021 with 720 KB drives, the 70 W "Universal ... power supply, with internal sensing", and the Starter Diskette.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 IBM, IBM Personal System/2 Hardware Maintenance Manual, S52G-9971-02, October 1994. Hosted on this wiki as IBM Personal System 2 Hardware Maintenance Manual (S52G-9971-02, October 1994) (PDF). Error codes 160–170 with FRU order and the lithium battery caution, p. 36; Models 30 and 30-286 power connector pin assignments, p. 138; Model 30 parts, p. 228; Model 30-286 parts, p. 230; system specifications for 8530-001 to E41, p. 435.
  5. ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 Louis Ohland, Tomáš Slavotínek et al., "8530 Planar (8086)", Ardent Tool of Capitalism. Designator maps of planars 61X8823, 33F4888 and 33F8474 (F1 "Mouse fuse?", F2 "Keyboard fuse?", F2 missing on the second Greenock board); riser card P/N 61X8864 and 61X8910 with the B1 BR-2/3A cell; and the full text of IBM retain tips H007157, H043664, H067282 and H094152.
  6. ↑ 6.0 6.1 6.2 Louis Ohland, Tomáš Slavotínek et al., "8530 286 Planar", Ardent Tool of Capitalism. Designator maps of the PGA and PLCC (FRU 34F0046) planars, including F1, J13 password override and ZM35 DS1287, and IBM retain tip H036143.
  7. ↑ 7.0 7.1 IBM, Personal System/2 Model 30 286 Guide to Operations, first edition, September 1988. Hosted on this wiki as IBM PS2 Model 30 286 Guide to Operations (PDF). "Cover Removal", p. 2-2; "Power-on Password Reset", pp. 3-4 and 3-5.
  8. ↑ 8.0 8.1 "60, 65 SX, and 80 – Common Devices", Ardent Tool of Capitalism. Peter Wendt on ALPS and Mitsubishi PS/2 diskette drives: both collect dust through the slot, which has no shield; the Mitsubishi 355 collects dirt on the head actuator spindle; ALPS drives lose the head-damper pad; Mitsubishi drives have capacitors that cause 6xx errors.
  9. ↑ 9.0 9.1 9.2 9.3 Louis Ohland, William R. Walsh, Tomáš Slavotínek et al., "8525 Planar", Ardent Tool of Capitalism. William Walsh on PS/2 diskette drives (dust, and replacing every surface-mount electrolytic on the drive board), the undocumented 1.44 MB support of the 8086 Model 25 and Model 30 with Sony drives, XT-IDE as the storage upgrade, and the Model 25 8086 using a different power connector from the Model 30 8086.
  10. ↑ 10.0 10.1 Louis Ohland, Tomáš Slavotínek et al., "8525 / 8530 Power", Ardent Tool of Capitalism. IBM's P3/P4 measurement limits for the Model 30 and 30-286, the minimum under-voltage sense levels, the Power Good reading of +3.5 to +5 V with the system running, and the procedure of removing adapters, cables and extra memory when Power Good is absent.
  11. ↑ 11.0 11.1 11.2 Ardent Tool of Capitalism, "PS/2 RTC/CMOS Batteries", based on content by Bob Eager and Peter H. Wendt. Model 30 (8086): 3 V battery, soldered, no FRU; the through-hole cell "was to be replaced with the entire riser board"; BR-2/3A, CR-2/3A and CR17335SE equivalents and the tab arrangement; AA and BH2/3A holders. Model 30-286: Dallas module FRU 8509237 (DS1287), replaced by the DS12887, DS12887+, DS1287A, DS12887A or bq3287MT, not the DS12C887; reworking the module with an external cell.
  12. ↑ 12.0 12.1 12.2 12.3 12.4 "PS/2 Error Codes", Ardent Tool of Capitalism, with the code tables for 160–199 and 300–999. The warm-boot warning, the battery note, 305 (keyboard voltage error; keyboard port fuse, keyboard cable, system board; "If no fuse in system replace system board"), 604 (unsupported drive or cable, drive must be media sense type) and 662 and 663 (wrong drive type, wrong media type; information only).
  13. ↑ 13.0 13.1 13.2 "IBM PS/2 Model 30", DOS Days. The drive fitting with no Molex connectors, the Model 30 fixed-disk interface being neither ESDI nor standard MFM, the drive caddy, and the Sony 1.44 MB drive that works in the 8086 machine.
  14. ↑ Mitsubishi Electric, 3.5 inch Flexible Disk Drive Standard Specifications, MF355C, UGD-0527A, February 1987. Hosted on this wiki as File:Mitsubishi MF355C 3.5 inch Diskette Drive Specifications (UGD-0527A, Feb 1987).pdf. Section 3: brushless DC direct-drive spindle motor at 300 rpm.
  15. ↑ "Known Problems – Experience, RETAIN Tips, ECAs", Ardent Tool of Capitalism. Peter Wendt on hard-disk stiction and ways to free a stuck drive.


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