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Created shared maintenance page for LC 630 series (covers LC 630, Quadra 630, Performa 630 series, and DOS Compatible variants)
 
Battery section corrected: the '4.5 battery' in Apple's symptom chart is a section cross-reference, not a voltage - the same manual prints '5.4 battery' for the same step and the Performa 630 Series manual prints '5.4' in the identical entry. Apple names no battery part, voltage or threshold for this machine, so none is asserted; 742-0011 is still correctly excluded
 
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Proper maintenance is essential to extending the lifespan and ensuring reliable operation of your '''Macintosh LC 630''', '''[[Macintosh Quadra 630|Quadra 630]]''', '''[[Macintosh Performa 630|Performa 630 series]]''', and '''[[Macintosh LC 630 DOS Compatible|LC 630 DOS Compatible]]'''. All these models share the same logic board (820-0524) and have identical maintenance requirements. The following sections provide guidance on cleaning, battery management, and preventive care.
This page covers routine care of the '''Macintosh LC 630''',
'''[[Macintosh Quadra 630|Quadra 630]]''', '''[[Macintosh Performa 630|Performa 630 series]]''' and
'''[[Macintosh LC 630 DOS Compatible|LC 630 DOS Compatible]]''', which Apple services as one family.<ref name="ss-630">Apple Computer, ''Service Source: LC 630 / Quadra 630 / Performa 640'' — covers the Macintosh LC 630, LC 630 DOS Compatible, Performa 640 DOS Compatible and Quadra 630. Hosted on this wiki as [[:File:Quadra.lc 630.performa 640.pdf]]; see [[LC 630/Quadra 630/ Performa 640 Service Source]].</ref>


== Regular Cleaning ==
== The machine in brief ==


=== Internal Cleaning ===
<templatestyles src="Template:StyledTable/styles.css" />
* Power off the system and disconnect all cables before opening
{| class="wikitable styled-table" style="width:90%;"
* Use the slide-out motherboard drawer for easy access (open rear panel, slide drawer out)
|+ Apple specification, 630 series<ref name="ss-630" />
* Use compressed air to remove dust from the logic board, power supply, and case vents
! Item !! Specification
* Pay attention to the passive cooling vents on the top and sides
|-
* Clean the CPU heat sink and surrounding area (dust accumulation causes overheating)
| Processor || LC 630: 68LC040 at 33 MHz. Quadra 630: 68040 with FPU at 33 MHz. LC 630 DOS Compatible: 68040 at 33 MHz plus an 80486DX2 at 66 MHz
* If a DOS Compatibility Card is installed, clean both PCBs carefully
|-
* Use an ESD brush with isopropyl alcohol for stubborn residue
| DRAM || 4 MB built in; 36 MB maximum on a one-slot board (661-0158), 52 MB on a two-slot board (661-1114). 72-pin, 80 ns or faster
* Ensure all fan openings and ventilation slots are clear
|-
| ROM || 1 MB
|-
| Video memory || A 1 MB DRAM frame buffer. Not expandable on any 630-series machine
|-
| Hard drive || IDE, 250 MB or 350 MB (500 MB on the DOS Compatible)
|-
| Sound || 8-bit monophonic input; 8-bit stereo output, 16-bit in CD mode
|-
| Expansion || 114-pin LC PDS; 112-pin communications slot; 60-pin video-in slot; 10-pin TV tuner connector
|-
| Line voltage || 100–240 VAC, 50–60 Hz
|-
| Maximum power || 45 W, monitor excluded
|-
| Height || 4.3 in (10.95 cm)
|-
| Weight || 17 lb (7.7 kg) without a CD-ROM drive; varies with options
|}


=== External and Case Cleaning ===
Apple's part numbers for the rest of the machine: power supply '''661-0170''', front panel control board
* Use a soft cloth dampened with water or mild detergent
'''661-0139''', floppy drive '''661-0121''', CD-ROM drive '''661-0913''', hard drive '''661-0070'''
* Avoid harsh chemicals on the case plastics (can accelerate yellowing)
(250 MB), '''661-0068''' (350 MB) or '''661-0146''' (500 MB), and the Macintosh Processor
* Clean the front panel volume buttons and headphone jack area
Upgrade card '''661-0255'''.<ref name="ss-630" />
* Remove dust from all external port openings
* Inspect the case for cracks (LC 630 plastics can become brittle)


=== Keyboard and Mouse Cleaning ===
== Getting inside ==
* Remove keycaps for thorough cleaning if using Apple Extended Keyboard
* Clean under keys with compressed air
* Wipe mouse ball and rollers with isopropyl alcohol (if mechanical)
* Inspect ADB cables for damage


== PRAM Battery Handling ==
Apple designed the 630 for quick service. Remove the rear plastic panel and the logic board slides
straight out of the chassis; remove the front plastic panel to reach the drives.<ref name="ss-630" /> Plastic panels
cover the metal bottom case, the top cover shield and the left, right and rear sides.<ref name="ss-630" />


=== Battery Specifications ===
Disconnect the mains lead first. The power supply is a separate mains-fed module — there is no CRT or
The LC 630 uses a '''4.5V alkaline battery''' (3× 1.5V cells in series):
analogue board in this machine, so with the supply's own cover on there is nothing at mains potential
* Part number: 742-0011
once the lead is out.
* Replacement: Rayovac 840 or equivalent 4.5V alkaline pack
* Expected lifespan: 3–5 years (less if system rarely powered on)
* Location: On logic board near rear I/O ports


=== Best Practices ===
== Regular cleaning ==
* Replace battery every 3 years regardless of function
* Remove battery if storing the system long-term
* Never use lithium batteries as a replacement (different voltage profile)
* Check battery voltage with multimeter—replace if below 4.0V
* Record PRAM settings before replacement (video, startup disk, date/time)


=== Cleaning Battery Leakage ===
* Blow the dust out of the logic board, the power supply, the fan and the case vents. The 630 has a fan
* Alkaline leakage appears as white crystalline deposits
  on a bracket that also carries the video daughterboard;<ref name="ss-630" /> a clogged fan is worth catching.
* Remove battery immediately if leakage is detected
* Clean the processor heat sink and the area around it.
* Use white vinegar to neutralize alkaline residue
* Clean the front-panel volume buttons and the headphone jack area. Apple lists jammed front-panel
* Follow with isopropyl alcohol cleaning
  control buttons as the cause of a constantly flashing menu bar or constant beeping, so they are worth
* Inspect nearby traces and components for corrosion
  keeping free.<ref name="ss-630" />
* Check continuity of affected traces with multimeter
* If a DOS Compatibility Card is fitted, clean all three of its boards.
* Repair damaged traces with jumper wires if necessary
* Case plastics: a soft cloth with water or mild detergent. Avoid solvents, which craze this era of ABS.
  For yellowing, see [[Retrobrite]].


== Connector and Socket Corrosion ==
== PRAM battery ==


=== Key Areas to Check ===
'''Apple's documentation for this machine names no battery part number, no voltage and no replacement threshold.''' The ''Service Source'' has no Battery Verification procedure, its exploded view lists no battery part, and its specifications give only "long-life lithium battery" for the clock and calendar.<ref name="ss-630" /> That is the honest position and nothing is invented here to fill it.
The slide-out motherboard design exposes connectors to handling wear:
* '''SIMM sockets''' – Oxidation prevents proper RAM contact
* '''CPU socket''' – 68040 processor pins susceptible to corrosion
* '''PDS slot''' – Critical for DOS Compatibility Card users
* '''Communication Slot''' – Check if modem or Ethernet installed
* '''Video input slot''' – Verify contacts if video card installed
* '''Power connector''' – Internal power cable connections
* '''IDE connector''' – Hard drive data cable connection


=== Cleaning Procedure ===
Two things are nevertheless settled:
* Apply DeoxIT or similar contact cleaner to affected sockets
* Use a soft brush to clean socket contacts
* Reseat all socketed ICs and expansion cards
* For stubborn oxidation, use a fiberglass pen carefully
* Verify proper seating after cleaning
* For DOS cards, clean both the CPU socket and PDS connections


== Common Failure Points ==
* '''Apple part 742-0011 is the LC-series part and does not belong here.''' It is the 3.6 V lithium half-AA that appears in the exploded view of the ''LC Series / Quadra 605'' manual, covering the [[Macintosh LC]], LC II, LC III, [[Macintosh LC 475|LC 475]] and [[Macintosh Quadra 605|Quadra 605]], and it appears nowhere in the 630 documentation.<ref name="ss-lc">Apple Computer, ''Service Source: Macintosh LC Series / Quadra 605'' — Specifications, Troubleshooting, Take Apart, Additional Procedures and Exploded View chapters. Hosted on this wiki as [[:File:Quadra 605.lc series.pdf]]; see [[Macintosh LC Series/ Quadra 605 Service Source]].</ref>
* '''"4.5 V" is a misreading, and so is "5.4 V".''' Apple's symptom charts for this machine contain the step "Unplug 4.5 battery, wait 20 seconds, plug in battery, and restart computer" in one entry and "Unplug '''5.4''' battery…" in another — the same instruction with two different numbers.<ref name="ss-630" /> Apple's ''Performa 630 Series Service Source'' prints "5.4" in the very entry where the LC 630 manual prints "4.5".<ref name="ss-p630">Apple Computer, ''Service Source: Macintosh Performa 630 Series''. Hosted on this wiki as [[:File:Performa 630 series.pdf]]; see [[Macintosh Performa 630 Series Service Source]]. Used here for the symptom-chart entry that the LC 630 manual prints with "4.5" and this manual prints with "5.4", which establishes that the figure is a cross-reference rather than a voltage.</ref> Those are section cross-references in Apple's own numbering, not voltages — no battery is both 4.5 V and 5.4 V. The genuine '''4.5 V pack''' in Apple's range belongs to the Performa 5000 series.


=== Surface-Mount Capacitor Leakage ===
So: '''read the cell in your own machine.''' Its chemistry and voltage are printed on it, and that is the only figure worth working from on this chassis.
The LC 630 logic board contains 9 surface-mount electrolytic capacitors:
* '''3× 100µF 6.3V''' – Power filtering
* '''6× 47µF 16V''' – Various filtering applications


Symptoms of failing capacitors:
What Apple does give is a diagnostic: where the machine is completely dead — no fan, no LED — its chart has you check external power, try a known-good keyboard, reseat the logic board, then '''unplug the battery, wait twenty seconds, plug it back in and restart'''.<ref name="ss-630" />
* Failure to power on or boot
* Intermittent crashes or freezing
* Visible brown residue around capacitor bases
* Corrosion on nearby traces


Refer to [[Macintosh LC 630 Capacitor Replacement Guide]] for complete specifications.
Take the battery out before the machine goes into storage. A leaking cell on a board of this age does damage that looks very like capacitor leakage and spreads under nearby chips. Identify the chemistry before choosing a neutraliser — bicarbonate of soda for a lithium cell, vinegar for an alkaline one; the wrong one makes the corrosion worse. For cleaning and trace repair see [[Battery Explosion, Capacitor or Corrosion Damage]]; for cell options see [[Battery Refurbishment]].
== Connector and socket care ==


=== IDE Controller Issues ===
The slide-out board design means the board gets handled, and the edge connectors and sockets take the
The LC 630 was Apple's first desktop Mac with IDE:
wear. Worth checking and reseating:
* Single device support only (no master/slave)
* Older System versions may not recognize modern drives
* PIO Mode 3 maximum (11.1 MB/s)
* 8 GB addressing limit


If experiencing drive issues:
* DRAM SIMM sockets — an eight-tone error chord at startup is Apple's documented symptom for a SIMM
* Update to System 7.5.2 or later
  problem, and its first instruction is simply to reseat them.<ref name="ss-630" />
* Use Apple Drive Setup 1.0.3 or newer
* The processor socket.
* Some drives require manufacturer formatting tools
* The LC PDS, communications slot and video-in slot.
* The monitor-out daughterboard connection on the fan bracket — Apple's second check for a dark
  screen when audio, drives and fan are all working.<ref name="ss-630" />
* The 40-pin IDE connector and the internal power connector.


=== PRAM Battery Damage ===
Reseat before you clean, and clean before you replace. Contact cleaner and a soft brush are enough for
Leaking batteries can destroy surrounding components:
oxidised sockets.
* Battery holder contacts corrode first
* Electrolyte spreads under nearby chips
* Trace damage may not be visible from above
* Corrosion can reach RAM sockets and CUDA chip
* Inspect thoroughly and repair traces as needed


=== Video Memory Limitations ===
== Common failure points ==
The LC 630 uses 1 MB DRAM shared with system operations:
* Cannot be upgraded
* Causes video flicker in some applications
* Performance penalty at higher resolutions
* No dedicated video RAM option


=== Passive Cooling Concerns ===
=== Surface-mount capacitor leakage ===
The LC 630 has no internal fan:
* Relies entirely on convection cooling
* Dust accumulation blocks airflow
* Keep ventilation slots clear
* Avoid stacking items on top of the unit
* Consider operating in climate-controlled environments


=== Front Panel Button Wear ===
The logic board carries nine surface-mount electrolytics: six 47 µF 16 V and three
The volume buttons can wear out with use:
100 µF 6.3 V.<ref name="ram-630">[https://recapamac.com.au/macintosh-lc630/ Recap-a-Mac — Macintosh LC 630]. Annotated photograph of the 820-0548-B logic board. Hosted on this wiki as [[:File:Mac LC 630 Recap Guide.jpg]]. Secondary source.</ref> Leakage causes lost or distorted sound, intermittent starting and
* Clean contacts with DeoxIT
corroded traces. Full specifications, the location map and the procedure are on
* Check ribbon cable connections
[[Macintosh LC 630 Capacitor Replacement Guide]].
* Replacement switches difficult to source
* Volume can be adjusted via software as alternative


== Voltage Adjustment and Power Checks ==
[[File:Mac LC 630 Recap Guide.jpg|center|thumb|650px|Macintosh LC 630 logic board 820-0548-B. The nine
surface-mount electrolytics are marked with their values and positive terminals. Source: Recap-a-Mac.]]


=== Power Supply Specifications ===
=== Error chords ===
Check these voltages at the logic board power connector:
* '''+5V rail:''' 4.85V – 5.15V (±3%)
* '''+12V rail:''' 11.9V – 12.7V (±6%)
* '''-12V rail:''' Check for correct polarity


=== Measurement Procedure ===
Apple's documented startup chords for this family:<ref name="ss-630" />
# Connect system to monitor, keyboard, and mouse
# Power on and allow to boot to desktop
# Measure voltages at power connector test points
# Adjust power supply potentiometer if out of spec
# Recheck after system has been running for 30 minutes


=== Power Supply Notes ===
{| class="wikitable styled-table" style="width:80%;"
* The LC 630 uses an internal power supply unit
! Symptom !! Apple's sequence
* Third-party replacement PSUs available
|-
* Recap PSU capacitors if original (same vintage concerns)
| Eight-tone error chord at startup || Reseat the SIMMs; replace the SIMMs; replace the logic board, keeping the customer's SIMMs
|-
| Four-tone error chord at startup || Disconnect the hard drive power cable and reboot; if that is clean, test and replace the hard drive. Then disconnect the floppy cable and reboot; if that is clean, replace the floppy drive. Then replace the logic board
|}


== DOS Compatibility Card Maintenance ==
See also [[Sad Mac Error Codes]].


For systems with the DOS Compatibility Card installed:
=== Video ===


=== Card Cleaning ===
The DB-15 monitor port is on a built-in video daughterboard, not on the logic board, and the daughterboard
* Remove card carefully (unplug from CPU socket and PDS)
is carried on the fan bracket.<ref name="ss-630" /> That changes the diagnosis of a dark screen:
* Clean both PCBs with compressed air
* Check 486 CPU heat sink for dust
* Clean joystick port contacts


=== Card Reseating ===
* '''Screen dark, audio and at least one drive working, fan running, LED lit:''' check the video
* DOS card connection issues are common after moves
  connections, then the monitor-out daughterboard connection on the fan bracket, then reseat the logic
* Reseat lower board in CPU socket firmly
  board, then adjust or replace the monitor.<ref name="ss-630" />
* Ensure upper board properly seated in PDS
* '''Part or all of the screen bright but no picture, audio present:''' reseat the logic board, then
* Verify joystick port alignment at rear panel
  replace the fan/video card bracket, then the monitor.<ref name="ss-630" />


=== Dedicated RAM ===
Video memory is a 1 MB DRAM frame buffer shared with the system. No 630-series machine supports
* Check DOS card SIMM if installed
video memory expansion — that is a design limit, not a fault.<ref name="ss-630" />
* Same SIMM specifications as motherboard slots
* Dedicated RAM improves PC performance


== Storage for Long-Term Preservation ==
=== IDE hard drive ===


* Remove PRAM battery before storage
The 630 was Apple's first desktop Macintosh with an IDE drive, and Apple flags the interface as new in
* Store in a cool, dry environment
its own manual. Its guidance is short: the internal IDE drive behaves like a SCSI drive from the system's
* Use anti-static bags for logic board if removed
point of view, IDE drives must be replaced like for like, and the IDE drive does not affect SCSI ID
* Document system configuration before storage
selection or termination. Seven external SCSI devices can still be daisy-chained from the external
* Consider archiving hard drive contents
port.<ref name="ss-630" />
* Remove any third-party expansion cards
 
For a flashing question mark at startup on a machine with empty PDS and communications slots, Apple's
sequence is: diagnose the drive with Disk First Aid; repair and update the driver with '''Drive Setup
1.0.3'''; if repair is impossible, back up, reformat with Drive Setup 1.0.3, update the driver and do a
clean install.<ref name="ss-630" /> Apple also requires System 7.1.2 or later on this family.<ref name="ss-630" />
 
=== TV tuner and video-in cards ===
 
Apple documents one specific hardware revision fault: if some UHF channels cannot be tuned, the Rev. A
video-in card '''661-0159''' should be replaced with the Rev. B card '''661-1073'''.<ref name="ss-630" /> On machines
with an MPEG card, video that will not play or a hang when playing is diagnosed by the chip at location
'''U12''': if it is marked 341S0205 the connections are at fault, and if it is not, the MPEG card is
replaced.<ref name="ss-630" />
 
== Things that are not faults ==
 
* '''No power switch.''' The 630 powers on exclusively through the soft power key on the keyboard. A
  machine that will not start with a suspect keyboard is a keyboard problem.<ref name="ss-630" />
* '''Crackling on sounds other than system beeps.''' Apple's fix is software: Audio Volume Extension 1.1
  or later.<ref name="ss-630" />
* '''Rattling at startup.''' On machines with the Apple External Video Connector fitted, Apple's remedy
  is to fold the cable away so that it stops touching the fan blades.<ref name="ss-630" />
* '''Video memory cannot be increased.''' See above.
 
== DOS Compatibility Card ==
 
The DOS-compatible machines carry three extra boards — the DOS-compatible board, a sound
daughterboard and an adapter board in the PDS — plus a DRAM SIMM on the main logic board. The DOS
board takes its own 72-pin, 80 ns or faster SIMMs, to 32 MB.<ref name="ss-630" />
 
Reseating after transport is the first thing to try when a DOS card stops being recognised: disconnect
the 26-pin adapter board cable, lift the battery end of the adapter board from the PDS, and refit both
squarely.<ref name="ss-630" /> Apple identifies a sound fault specific to DOS-compatible machines with replacement
part 661-0253.<ref name="ss-630" />
 
== Storage ==
 
* Remove the battery.
* Store cool and dry, and not in a sealed plastic bag with the machine still warm.
* Take out third-party expansion cards, and note the configuration somewhere you will find it again.
* Back up the IDE drive before it becomes the only copy.
 
== Related pages ==


== Related Maintenance Pages ==
* [[Macintosh LC 630]]
* [[Macintosh LC 630]]
* [[Macintosh LC 630 Capacitor Replacement Guide]]
* [[Macintosh LC 630 Troubleshooting]]
* [[Macintosh LC 630 DOS Compatible]]
* [[Macintosh LC 630 DOS Compatible]]
* [[Macintosh LC 630 Troubleshooting]]
* [[Macintosh LC 630 Capacitor Replacement Guide]]
* [[Macintosh Quadra 630]]
* [[Macintosh Quadra 630]]
* [[Macintosh Performa 630]]
* [[Macintosh Performa 630]]
* [[LC 630/Quadra 630/ Performa 640 Service Source]]
* [[Hard Drive Maintenance and Repair]]
* [[Recommended Tools]]
== References ==
<references />


[[Category:Apple Vintage Computers]]
[[Category:Apple Vintage Computers]]
[[Category:Apple Maintenance Guides]]
[[Category:Apple Maintenance Guides]]
{{Navbox-AppleVintage|state=collapsed}}

Latest revision as of 21:13, 23 September 2026

This page covers routine care of the Macintosh LC 630, Quadra 630, Performa 630 series and LC 630 DOS Compatible, which Apple services as one family.[1]

The machine in brief

[edit | edit source]
Apple specification, 630 series[1]
Item Specification
Processor LC 630: 68LC040 at 33 MHz. Quadra 630: 68040 with FPU at 33 MHz. LC 630 DOS Compatible: 68040 at 33 MHz plus an 80486DX2 at 66 MHz
DRAM 4 MB built in; 36 MB maximum on a one-slot board (661-0158), 52 MB on a two-slot board (661-1114). 72-pin, 80 ns or faster
ROM 1 MB
Video memory A 1 MB DRAM frame buffer. Not expandable on any 630-series machine
Hard drive IDE, 250 MB or 350 MB (500 MB on the DOS Compatible)
Sound 8-bit monophonic input; 8-bit stereo output, 16-bit in CD mode
Expansion 114-pin LC PDS; 112-pin communications slot; 60-pin video-in slot; 10-pin TV tuner connector
Line voltage 100–240 VAC, 50–60 Hz
Maximum power 45 W, monitor excluded
Height 4.3 in (10.95 cm)
Weight 17 lb (7.7 kg) without a CD-ROM drive; varies with options

Apple's part numbers for the rest of the machine: power supply 661-0170, front panel control board 661-0139, floppy drive 661-0121, CD-ROM drive 661-0913, hard drive 661-0070 (250 MB), 661-0068 (350 MB) or 661-0146 (500 MB), and the Macintosh Processor Upgrade card 661-0255.[1]

Getting inside

[edit | edit source]

Apple designed the 630 for quick service. Remove the rear plastic panel and the logic board slides straight out of the chassis; remove the front plastic panel to reach the drives.[1] Plastic panels cover the metal bottom case, the top cover shield and the left, right and rear sides.[1]

Disconnect the mains lead first. The power supply is a separate mains-fed module — there is no CRT or analogue board in this machine, so with the supply's own cover on there is nothing at mains potential once the lead is out.

Regular cleaning

[edit | edit source]
  • Blow the dust out of the logic board, the power supply, the fan and the case vents. The 630 has a fan
 on a bracket that also carries the video daughterboard;[1] a clogged fan is worth catching.
  • Clean the processor heat sink and the area around it.
  • Clean the front-panel volume buttons and the headphone jack area. Apple lists jammed front-panel
 control buttons as the cause of a constantly flashing menu bar or constant beeping, so they are worth
 keeping free.[1]
  • If a DOS Compatibility Card is fitted, clean all three of its boards.
  • Case plastics: a soft cloth with water or mild detergent. Avoid solvents, which craze this era of ABS.
 For yellowing, see Retrobrite.

PRAM battery

[edit | edit source]

Apple's documentation for this machine names no battery part number, no voltage and no replacement threshold. The Service Source has no Battery Verification procedure, its exploded view lists no battery part, and its specifications give only "long-life lithium battery" for the clock and calendar.[1] That is the honest position and nothing is invented here to fill it.

Two things are nevertheless settled:

  • Apple part 742-0011 is the LC-series part and does not belong here. It is the 3.6 V lithium half-AA that appears in the exploded view of the LC Series / Quadra 605 manual, covering the Macintosh LC, LC II, LC III, LC 475 and Quadra 605, and it appears nowhere in the 630 documentation.[2]
  • "4.5 V" is a misreading, and so is "5.4 V". Apple's symptom charts for this machine contain the step "Unplug 4.5 battery, wait 20 seconds, plug in battery, and restart computer" in one entry and "Unplug 5.4 battery…" in another — the same instruction with two different numbers.[1] Apple's Performa 630 Series Service Source prints "5.4" in the very entry where the LC 630 manual prints "4.5".[3] Those are section cross-references in Apple's own numbering, not voltages — no battery is both 4.5 V and 5.4 V. The genuine 4.5 V pack in Apple's range belongs to the Performa 5000 series.

So: read the cell in your own machine. Its chemistry and voltage are printed on it, and that is the only figure worth working from on this chassis.

What Apple does give is a diagnostic: where the machine is completely dead — no fan, no LED — its chart has you check external power, try a known-good keyboard, reseat the logic board, then unplug the battery, wait twenty seconds, plug it back in and restart.[1]

Take the battery out before the machine goes into storage. A leaking cell on a board of this age does damage that looks very like capacitor leakage and spreads under nearby chips. Identify the chemistry before choosing a neutraliser — bicarbonate of soda for a lithium cell, vinegar for an alkaline one; the wrong one makes the corrosion worse. For cleaning and trace repair see Battery Explosion, Capacitor or Corrosion Damage; for cell options see Battery Refurbishment.

Connector and socket care

[edit | edit source]

The slide-out board design means the board gets handled, and the edge connectors and sockets take the wear. Worth checking and reseating:

  • DRAM SIMM sockets — an eight-tone error chord at startup is Apple's documented symptom for a SIMM
 problem, and its first instruction is simply to reseat them.[1]
  • The processor socket.
  • The LC PDS, communications slot and video-in slot.
  • The monitor-out daughterboard connection on the fan bracket — Apple's second check for a dark
 screen when audio, drives and fan are all working.[1]
  • The 40-pin IDE connector and the internal power connector.

Reseat before you clean, and clean before you replace. Contact cleaner and a soft brush are enough for oxidised sockets.

Common failure points

[edit | edit source]

Surface-mount capacitor leakage

[edit | edit source]

The logic board carries nine surface-mount electrolytics: six 47 µF 16 V and three 100 µF 6.3 V.[4] Leakage causes lost or distorted sound, intermittent starting and corroded traces. Full specifications, the location map and the procedure are on Macintosh LC 630 Capacitor Replacement Guide.

Macintosh LC 630 logic board 820-0548-B. The nine surface-mount electrolytics are marked with their values and positive terminals. Source: Recap-a-Mac.

Error chords

[edit | edit source]

Apple's documented startup chords for this family:[1]

Symptom Apple's sequence
Eight-tone error chord at startup Reseat the SIMMs; replace the SIMMs; replace the logic board, keeping the customer's SIMMs
Four-tone error chord at startup Disconnect the hard drive power cable and reboot; if that is clean, test and replace the hard drive. Then disconnect the floppy cable and reboot; if that is clean, replace the floppy drive. Then replace the logic board

See also Sad Mac Error Codes.

Video

[edit | edit source]

The DB-15 monitor port is on a built-in video daughterboard, not on the logic board, and the daughterboard is carried on the fan bracket.[1] That changes the diagnosis of a dark screen:

  • Screen dark, audio and at least one drive working, fan running, LED lit: check the video
 connections, then the monitor-out daughterboard connection on the fan bracket, then reseat the logic
 board, then adjust or replace the monitor.[1]
  • Part or all of the screen bright but no picture, audio present: reseat the logic board, then
 replace the fan/video card bracket, then the monitor.[1]

Video memory is a 1 MB DRAM frame buffer shared with the system. No 630-series machine supports video memory expansion — that is a design limit, not a fault.[1]

IDE hard drive

[edit | edit source]

The 630 was Apple's first desktop Macintosh with an IDE drive, and Apple flags the interface as new in its own manual. Its guidance is short: the internal IDE drive behaves like a SCSI drive from the system's point of view, IDE drives must be replaced like for like, and the IDE drive does not affect SCSI ID selection or termination. Seven external SCSI devices can still be daisy-chained from the external port.[1]

For a flashing question mark at startup on a machine with empty PDS and communications slots, Apple's sequence is: diagnose the drive with Disk First Aid; repair and update the driver with Drive Setup 1.0.3; if repair is impossible, back up, reformat with Drive Setup 1.0.3, update the driver and do a clean install.[1] Apple also requires System 7.1.2 or later on this family.[1]

TV tuner and video-in cards

[edit | edit source]

Apple documents one specific hardware revision fault: if some UHF channels cannot be tuned, the Rev. A video-in card 661-0159 should be replaced with the Rev. B card 661-1073.[1] On machines with an MPEG card, video that will not play or a hang when playing is diagnosed by the chip at location U12: if it is marked 341S0205 the connections are at fault, and if it is not, the MPEG card is replaced.[1]

Things that are not faults

[edit | edit source]
  • No power switch. The 630 powers on exclusively through the soft power key on the keyboard. A
 machine that will not start with a suspect keyboard is a keyboard problem.[1]
  • Crackling on sounds other than system beeps. Apple's fix is software: Audio Volume Extension 1.1
 or later.[1]
  • Rattling at startup. On machines with the Apple External Video Connector fitted, Apple's remedy
 is to fold the cable away so that it stops touching the fan blades.[1]
  • Video memory cannot be increased. See above.

DOS Compatibility Card

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The DOS-compatible machines carry three extra boards — the DOS-compatible board, a sound daughterboard and an adapter board in the PDS — plus a DRAM SIMM on the main logic board. The DOS board takes its own 72-pin, 80 ns or faster SIMMs, to 32 MB.[1]

Reseating after transport is the first thing to try when a DOS card stops being recognised: disconnect the 26-pin adapter board cable, lift the battery end of the adapter board from the PDS, and refit both squarely.[1] Apple identifies a sound fault specific to DOS-compatible machines with replacement part 661-0253.[1]

Storage

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  • Remove the battery.
  • Store cool and dry, and not in a sealed plastic bag with the machine still warm.
  • Take out third-party expansion cards, and note the configuration somewhere you will find it again.
  • Back up the IDE drive before it becomes the only copy.
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References

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  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 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 Apple Computer, Service Source: LC 630 / Quadra 630 / Performa 640 — covers the Macintosh LC 630, LC 630 DOS Compatible, Performa 640 DOS Compatible and Quadra 630. Hosted on this wiki as File:Quadra.lc 630.performa 640.pdf; see LC 630/Quadra 630/ Performa 640 Service Source.
  2. ↑ Apple Computer, Service Source: Macintosh LC Series / Quadra 605 — Specifications, Troubleshooting, Take Apart, Additional Procedures and Exploded View chapters. Hosted on this wiki as File:Quadra 605.lc series.pdf; see Macintosh LC Series/ Quadra 605 Service Source.
  3. ↑ Apple Computer, Service Source: Macintosh Performa 630 Series. Hosted on this wiki as File:Performa 630 series.pdf; see Macintosh Performa 630 Series Service Source. Used here for the symptom-chart entry that the LC 630 manual prints with "4.5" and this manual prints with "5.4", which establishes that the figure is a cross-reference rather than a voltage.
  4. ↑ Recap-a-Mac — Macintosh LC 630. Annotated photograph of the 820-0548-B logic board. Hosted on this wiki as File:Mac LC 630 Recap Guide.jpg. Secondary source.
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