Editing Macintosh SE/30 Troubleshooting

This guide covers the faults an SE/30 actually presents with: dead machines, the simasimac pattern, collapsed rasters, Chimes of Death, SCSI and floppy problems, and the bench technique for bringing a board up from nothing.

Before diagnosing anything electronic, deal with the leakage. '''Every''' SE/30 has leaking surface-mount electrolytics on the logic board, and the electrolyte is conductive and corrosive.<ref name="recapse30" /> A great many "faulty chip" diagnoses on this machine turn out to be a severed trace or a corroded via. Recap and clean first, then troubleshoot — see [[Macintosh SE/30 Capacitor Replacement Guide]].

<templatestyles src="Template:StyledTable/styles.css" />

== Preliminary Checks and Power Supply Basics ==

The SE/30 has three separate modules behind the logic board: a power supply (Apple 661-0370), an analogue board (661-0371) and a video board (982-0024). All three are shared with the Macintosh SE.<ref name="ssse30" /> Knowing which one you are accusing matters.

{{Warning|The CRT anode holds charge after power-off — discharge it before working on the analogue board, the video board or the CRT socket board. See [[CRT Discharge Procedure]]. The power supply's primary reservoir (620&nbsp;µF 400&nbsp;V, or a series pair of 330&nbsp;µF 200&nbsp;V depending on which unit is fitted) also stays charged; measure across it before touching the primary side.<ref name="c5se" />}}

Apple rates the machine at 120–240&nbsp;V AC, automatically configured, 48–62&nbsp;Hz, 75&nbsp;W maximum.<ref name="ssse30" /> Apple's Service Source publishes '''no rail tolerances and no voltage adjustment procedure''' for the SE/30 — there is no trimmer to turn. Its symptom chart sends a completely dark machine with a stopped fan to the power supply first, then the analogue board.<ref name="ssse30" />

{| class="wikitable"
|+
![[File:Analog connector front.png|none|thumb|274x274px|Macintosh SE/30 logic board analogue connector (front)]]
![[File:Analog connector back.png|none|thumb|311x311px|Macintosh SE/30 logic board analogue connector (back)]]
|}

If the unit is completely dead — no fan, no CRT glow, no chime — the analogue board is the usual culprit, and Larry Pina narrows it to specific components:<ref name="dms" />

* '''A dreadful hissing or sizzling noise with a dark screen''' — rectifier '''CR2''' shorted (0.00–0.01&nbsp;Ω). It is a GI854 barrel rectifier, R-51, 600&nbsp;V 3&nbsp;A; Pina fits an MR824 (R-51, 400&nbsp;V, 5&nbsp;A) instead to stop it recurring.
* '''Dead with no hissing noise''' — rectifier '''CR3''' shorted, same part. Then check the '''BU4060''' horizontal output transistor at '''Q2''' for burning, and after that the flyback at '''T2'''.

Also worth doing before anything else:

* Disconnect every external peripheral and any PDS card.
* Check the logic board for PRAM battery corrosion, and remove the cell. Apple's threshold for replacement is '''below 2.8&nbsp;V'''.<ref name="ssse30" />
* Replace all of the electrolytic capacitors on the logic board and check trace continuity around every one of them.

=== Power Rails ===

The logic board takes power and video through '''J12''', Apple's "Power & Video Connector", a 14-way header. The pinout below is from Apple engineering drawing 050-0253-01 as redrawn by the ''macse30mlb'' project, and has been checked pin by pin against that schematic.<ref name="se30sch" />

{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+ '''J12 — power and video connector'''
|-
! Pin !! Signal
|-
| 1–5 || Ground
|-
| 6 || −5 V
|-
| 7 || −12 V
|-
| 8 || Ground
|-
| 9 || Video out
|-
| 10 || Horizontal sync
|-
| 11 || Vertical sync
|-
| 12, 13 || +5 V
|-
| 14 || +12 V
|}

That pinout makes bench-powering a bare logic board practical, and it tells you what each rail is for:

* '''+12&nbsp;V (pin 14)''' feeds the internal and external floppy drives, the PDS connector and the sound circuit — J6, J8, J13 and UB10/UB11/UA9. A board will come up to a point without it, '''but the sound chip UB11 will hold the system in reset''', so the furthest you will get is horizontal lines or a simasimac screen.
* '''−12&nbsp;V (pin 7)''' goes only to the PDS slot (J13), so a bare board boots without it.
* '''−5&nbsp;V (pin 6)''' feeds the printer and modem line drivers (UE12, UD12) and the PDS slot, so a bare board boots without it too.
* '''+5&nbsp;V (pins 12 and 13)''' goes everywhere else. It is not optional.

With +5&nbsp;V alone you should see video output on pins 9, 10 and 11 on an oscilloscope, but the machine will not progress past horizontal lines because UB11 holds !RESET at around 2.5&nbsp;V. Add +12&nbsp;V to get further.<ref name="retrosixpin" />

== "Simasimac" — Horizontal Stripe Pattern ==

[[File:Simasimac issue.jpg|thumb|Macintosh SE/30 simasimac pattern]]

The simasimac pattern — alternating horizontal black-and-white bands with no startup chime — is not a video fault. The video circuit is running perfectly; it is drawing whatever happens to be in video memory because the processor never got out of reset or never completed its startup tests. On an SE/30 the cause is nearly always leakage damage.

Work through:

* '''Recap and clean the logic board first.''' Everything below is wasted effort on a board still covered in electrolyte.
* Check continuity on traces and vias around every capacitor, particularly under the Ux8 row and around the sound chips.
* Clean and reseat the ROM SIMM and the RAM SIMMs.
* Check that the CPU is being released from reset (see [[#The !RESET line|The !RESET line]] below); a sound chip with no 12&nbsp;V rail, or a failed one, will hold it down.
* Check the processor clock. Apple specifies the SE/30's 68030 at '''15.667&nbsp;MHz'''<ref name="ssse30" /> — commonly rounded to 16&nbsp;MHz in conversation, but the figure to expect on a counter is 15.667.
* Inspect the Apple Sound Chip at '''UE10''' and the Sony sound chip at '''UB11''', and the resistor pack RP2 beside them.
* Replace the PRAM cell if it reads below 2.8&nbsp;V.<ref name="ssse30" />

== Single Vertical Line — Horizontal Sweep Collapse ==

A picture that has collapsed to a '''single vertical line''' is a failure of the '''horizontal''' sweep. This is common on both the [[Macintosh SE]] and the SE/30, which share an analogue board.<ref name="ssse30" />

'''Switch the machine off the moment you see it.''' A concentrated line will burn the phosphor permanently within minutes.

The culprits, in the order worth checking:

# '''Cracked joints at the yoke connector (P1 / J1).''' Thermal cycling over decades fatigues these joints, and this is by a wide margin the most common analogue-board fault on a compact Mac. Reflow all four pins with fresh solder while the connector halves are still mated, or the heat will distort the plastic and you will not get them back together.<ref name="cmrn" /> Pina also notes the plug itself is often burned by this stage and may need replacing.<ref name="dms" />
# '''C15.''' The non-polarised high-frequency capacitor in the horizontal circuit, 3.9&nbsp;µF 35&nbsp;V bipolar low-ESR.<ref name="c5147" /> Pina specifies it as 3.9&nbsp;µF NP 25/35&nbsp;V HF and recommends replacing it with a '''3.9&nbsp;µF NP 100&nbsp;V HF''' part. Its failure shows first as poor horizontal linearity — items on the left wider than items on the right — then as a bright vertical line, then as smoke.<ref name="dms" />
# '''R19.''' 220&nbsp;Ω, ½&nbsp;W, 5&nbsp;%. When it burns out the machine chimes normally but shows a relatively dim vertical line. Pina adds that linearity coil '''L3''' should be vacuum-desoldered and resoldered with fresh solder at the same time, or the fault returns.<ref name="dms" />

A '''single horizontal line''' is the opposite fault — a collapse of the '''vertical''' sweep, a different circuit. Apple adopted the TDA1170 vertical deflection IC on the compact Macs after the Plus, and that is where to look.<ref name="cmrn" />

== Chimes of Death and Sad Mac Codes ==

The Chimes of Death signify a failure during the startup memory tests — usually RAM, ROM or the paths between them and the processor.

* Use four matched SIMMs per bank; put the larger-capacity pair in '''Bank A'''.
* Clean and reseat the ROM SIMM.
* Check address and data continuity around the capacitors — on an SE/30 a broken trace mimics a failed chip exactly.
* Suspect the '''F258''' RAM multiplexers above the ROM slot. Recap-a-Mac reports these failing increasingly often, and the symptom is Sad Mac chimes with known-good RAM.<ref name="recapse30" />
* Check the VIAs for corrosion and overheating.

The Sad Mac code on screen narrows this down considerably. See [[Sad Mac Error Codes]] — the decoding there is original research native to this wiki.

== Video Display Issues ==

Apple's own symptom chart is module-level, but it establishes the order of suspicion: a dark screen with working audio and drives goes brightness control, video cable, analogue board, video board, logic board, CRT; a bright screen with no video information goes analogue board, video board, logic board.<ref name="ssse30" />

=== No video but chime present ===
* Turn the brightness control clockwise. Apple lists this first for a reason.
* Confirm the CRT filament is glowing.
* Check the video multiplexer circuit — the row of Ux8 ICs below the large axial capacitor is a known casualty of capacitor leakage.<ref name="recapse30" />
* Probe video and sync at J12 pins 9, 10 and 11.
* If the machine chimes, the fan turns and a hard disk spins but the screen stays dark and the brightness control does nothing, check '''R22''' on the analogue board — 470&nbsp;kΩ, ½&nbsp;W, 5&nbsp;%, which fails open.<ref name="dms" />

=== Vertical "jailbar" stripes ===
* Usually a RAM configuration problem: use identical SIMMs in each bank, larger pair in Bank A.

=== Checkerboard pattern ===
[[File:Macintosh SE-30 Checkerboard.png|thumb|Checkerboard error screen]]

* Typically a ROM failure. Clean and reseat the ROM SIMM.
* Confirm the ROM is the right one — an SE/30 or IIsi ROM.

== Disk Drive and SCSI Issues ==

=== Frozen mouse on a grey screen ===
* Suspect the SCSI controller. The SE/30 uses an NCR 53C80 at '''UI12'''.<ref name="se30sch" />
* Disconnect every internal and external SCSI device and retry.
* Inspect the termination resistors.

=== Floppy drive issues ===
* A dirty or dried-out mechanism is the most common cause by far — see [[Macintosh Floppy Drive Maintenance]].
* The SWIM controller is at '''UJ11'''.<ref name="se30sch" />
* Cracked or corroded joints on the VIA and SWIM packages.

== Audio and ADB Issues ==

=== No sound ===
* The SE/30 has two sound ICs: the Apple Sound Chip at '''UE10''' and the Sony sound chip at '''UB11'''.<ref name="se30sch" /> Both sit in an area that capacitor leakage reaches, and audio faults after leakage are common.
* Test at the headphone jack to separate the logic board from the internal speaker and the analogue board's amplifier.

=== ADB not working ===
* '''Fuse F1 on the logic board''' is a 1&nbsp;A fuse; a dead keyboard and mouse on an otherwise healthy machine is very often this.<ref name="se30sch" />
* The ADB transceiver is at '''UL11'''.<ref name="se30sch" />
* Cracked or corroded joints on the VIAs.

== Reset and Clock Problems ==

* '''Random resets''' — check rail stability at J12.
* '''Time not retained''' — a dead PRAM cell, or the 32.768&nbsp;kHz crystal '''Y1'''.<ref name="se30sch" />
* Look for electrolyte residue around the ADB transceiver and the VIAs.

Check the crystals first, because almost nothing on the board works without them. On an oscilloscope, Y1 (the crystal nearest the ROM, front right) should show a 32.768&nbsp;kHz sine wave, squarer on the top pad, around 3–4&nbsp;V peak to peak. ''(Waveform amplitude measured on the bench for this wiki; the crystal frequency is from the schematic.)''<ref name="se30sch" />

=== The !RESET line ===

The video output circuit runs regardless of the state of the reset line — which is why you can see horizontal lines or simasimac on a board that is going nowhere — but nothing useful happens until the processor is released from reset.

!RESET connects to:

* 68030 CPU ('''UK8''') — bidirectional
* VIA1 ('''UK12''') pin 37
* VIA2 ('''UK11''') pin 37
* ADB transceiver ('''UL11''') pin 4
* SWIM floppy controller ('''UJ11''') pin 25
* 53C80 SCSI controller ('''UI12''') pin 7
* Apple Sound Chip ('''UE10''') pin 40
* Sony sound chip ('''UB11''') pin 5

Any of these can hold !RESET low if it has failed, even where the pin is nominally an input.<ref name="retrosixboot" />

== Minimal Boot Requirements ==

If there is no bus activity, no chime and no video, start from the absolute minimum and look for the address bus toggling continuously at power-up, or for the startup chime.

The initial startup is handled by the glue logic chip '''UI8'''.

=== Critical ICs ===

* 68030 CPU (UK8)
* Glue logic (UI8)
* RAM signals PAL (UH7)
* 68k / video signals PAL (UI6)
* Pull-up resistor packs (RP7, RP9)
* Sound IC (UE10)
* ROM (J14) if you want to hear the startup sounds; otherwise watch the address bus on a scope

To run from +5&nbsp;V alone, remove the sound chips and wire up the headphone port so you can still hear audio:

[[File:SE-30 5v Power Bridge.png|thumb|312x312px|SE/30 +5&nbsp;V power bridge]]

* Remove UB10 and UB11.
* Bridge UB11 pins 8 and 9 to tie the analogue and digital grounds together. Audio will be a little noisy. This also restores the S2 NMI button, which stops working once UB11 is out because the analogue and digital grounds are separated and the button uses the disconnected one. '''Note: S1, the normal reset button, will not work with UB10 removed''' — UB10 senses that button and pulls reset low. Use S2 or cycle the power instead.<ref name="retrosixboot" />

=== Non-essential ICs ===

If a failing chip is dragging a rail or a bus line down, these can all come out:

* UD1
* UK4 (RTC)
* UD12 / UE12 / UG12 / UI12
* UK12 / UJ11 / UK11 / UL11
* UI5 (FPU)
* All RAM — if the board passes its RAM check but UG12, UI12 or UJ11 are missing or faulty you will get no beep and horizontal lines
* UK6 (video IC)
* UE6 / UG6 / UE7 / UG7 (PALs)
* UC6 / UC7 (video RAM)
* UA8 / UB8 / UC8 / UD8 / UE8 / UF8 / UG8
* UI2 / UJ2 / UI3 / UJ3 / UJ4 / UI4 / UJ6 (logic)
* RP1 / RP4 / RP5 / RP6 / RP8 (resistor packs)

=== Expected result ===

With only the critical ICs fitted, the sound chip removed and the headphone jack bridged, applying power should produce a Sad Mac boot sound. Without a ROM fitted, probe the lower address pins of the ROM socket instead — they should pulse continuously.

If neither happens, check that every chip on the !RESET list above is letting the line go high.<ref name="retrosixboot" />

== Initial Boot Sequence ==

Once the glue logic chip has brought the 68030's pins to their initial state, the processor starts walking the bus, and the address pins toggle continuously as it loops attempting a load.

The 68030's reset signal is bidirectional: it can both assert reset and be reset from outside. The minimum needed to see activity is:

* VCC at 5&nbsp;V
* A valid clock
* !RESET high
* !HALT high

[[File:68k pinout and diagram.jpg|none|thumb|756x756px|Macintosh SE/30 68030 pinout and diagram]]

=== !BERR ===

When the 68030 accesses memory or an I/O device and something goes wrong — a bad access, a parity error, a missing data acknowledge — a bus error is generated. Whichever device the processor was talking to pulls !BERR low, and the processor stops and enters its error handler. !BERR toggling low is therefore a sign that something on the address or data bus is unhappy.

On the SE/30, !BERR connects to:

* 68030 CPU (UK8)
* PAL1644B (UI6)
* Glue chip (UI8)
* PDS header (J13)

It is pulled up to +5&nbsp;V through resistor pack '''RP7''' (1&nbsp;kΩ), so verify that pack is present and pulling high before reading anything into the signal.<ref name="se30sch" /> Since !BERR is an input to the processor and the PDS header is normally empty during a bare-board boot, the glue chip or the PAL is what must be driving it low.<ref name="retrosixboot" />

== Analogue Board Fault Summary ==

{| class="wikitable styled-table" style="width:100%;"
|-
! Symptom !! Where to look
|-
| Single '''vertical''' line || Horizontal sweep collapse — reflow the yoke plug P1, then C15 (3.9&nbsp;µF NP), then R19 (220&nbsp;Ω) and linearity coil L3<ref name="dms" />
|-
| Single '''horizontal''' line || Vertical sweep collapse — the TDA1170 vertical deflection IC and its surrounding circuit<ref name="cmrn" />
|-
| Chimes, fan and drive run, screen dark, brightness has no effect || R22 open (470&nbsp;kΩ, ½&nbsp;W, 5&nbsp;%)<ref name="dms" />
|-
| Right side of the picture shakes during disk access or when a window opens || CR2, then Q2 (BU4060)<ref name="dms" />
|-
| Dead with a hissing or sizzling noise || CR2 shorted<ref name="dms" />
|-
| Dead with no noise at all || CR3 shorted, then Q2, then flyback T2<ref name="dms" />
|-
| Wavy or distorted picture, high-pitched noise || Failing flyback
|}

== Related Pages ==
* [[Macintosh SE/30]]
* [[Macintosh SE/30 General Maintenance]]
* [[Macintosh SE/30 Capacitor Replacement Guide]]
* [[Macintosh SE Capacitor Replacement Guide]]
* [[Sad Mac Error Codes]]
* [[Capacitor Failure Symptoms]]
* [[Battery Explosion, Capacitor or Corrosion Damage]]
* [[CRT Discharge Procedure]]
* [[Macintosh Floppy Drive Maintenance]]

== References ==
<references>
<ref name="ssse30">Apple Computer, ''Macintosh SE/30 Service Source'', hosted here as [[:File:Macintosh SE30.pdf]]. Specifications (Processor 15.667&nbsp;MHz, Electrical), Troubleshooting symptom charts, Additional Procedures — Battery Verification (2.8&nbsp;V threshold), Adjustments (Yoke and Video only — no voltage adjustment exists) and the Exploded View module part numbers.</ref>
<ref name="se30sch">''macse30mlb'' — a KiCad redrawing of Apple engineering drawing 050-0253-01, the Macintosh SE/30 main logic board schematic. https://github.com/mishimasensei/macse30mlb Source for the J12 pinout (verified pin by pin against sheet 9, "Power Connector, Pullups &amp; Pulldowns"), fuse F1 (1&nbsp;A), crystal Y1 (32.768&nbsp;kHz), resistor pack RP7 (1&nbsp;kΩ) and the chip designators used on this page. Recommended by Recap-a-Mac as the diagnostic schematic for this machine.</ref>
<ref name="recapse30">Bruce / Recap-a-Mac, "Macintosh SE/30". https://recapamac.com.au/macintosh-se-30/ On universal capacitor leakage, damage to the Ux8 video multiplexer row, and failing F258 RAM multiplexers presenting as Sad Mac chimes with good RAM. Secondary source, derived from repeated repairs.</ref>
<ref name="dms">Larry Pina, ''The Dead Mac Scrolls'' (1992), hosted here as [[:File:The Dead Mac Scrolls 1992.pdf]], "Mac SE and SE/30" section. Symptom-to-component diagnoses with exact part specifications for CR2, CR3, Q2, R19, R22, C15, P1 and T2.</ref>
<ref name="c5147">Console5 TechWiki, "Mac Analog Board: 630-0147" — the SE / SE/30 analogue board, including C15 at 3.9&nbsp;µF 35&nbsp;V bipolar low-ESR. https://wiki.console5.com/wiki/Mac_Analog_Board:_630-0147 Secondary source.</ref>
<ref name="c5se">Console5 TechWiki, "Macintosh SE" — the three power supply variants fitted to the SE and SE/30 and their primary-side capacitor ratings. https://wiki.console5.com/wiki/Macintosh_SE Secondary source.</ref>
<ref name="cmrn">Thomas H. Lee, ''Classic Mac Repair Notes'', revision of 31 May 2007 (©2000 Thomas H. Lee, all rights reserved; not re-hosted here for that reason). https://archive.org/details/Classic_Mac_Repair_Notes Section 4.1 on yoke connector joints and the symptoms they produce, and section 7.3 on the TDA1170 vertical deflection IC used in compact Macs after the Plus.</ref>
<ref name="retrosixpin">RetroSix Wiki, "Power / AV Pinout (Macintosh SE/30)" and "Basics (Macintosh SE/30)". https://www.retrosix.wiki/basics-macintosh-se30 Which subsystems each rail feeds and how far a board boots without each one.</ref>
<ref name="retrosixboot">RetroSix Wiki, "Minimum Boot (Macintosh SE/30)", "Very Minimal Boot (Macintosh SE/30)" and "68k Initial Boot (Macintosh SE/30)". https://www.retrosix.wiki/basics-macintosh-se30 Critical and non-essential IC lists, the UB10/UB11 removal and pin 8–9 ground bridge, and the !RESET and !BERR analysis. Parts of these pages require a RetroSix account to read in full.</ref>
</references>

[[Category:Apple Vintage Computers]]
[[Category:Apple Troubleshooting Guides]]