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Macintosh Quadra 840AV Service Source

From RetroTechCollection

The Macintosh Quadra 840AV Service Source is Apple's 86-page service manual for the Macintosh Quadra 840AV. The PDF was distilled from FrameMaker files on 2 January 1996. Its title page carries no Apple part number or revision.

Like other Service Source volumes it works at module level: specifications, symptom charts, take-apart and upgrade procedures, battery and reset procedures, and an exploded view with module part numbers.

Contents

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Page numbers are positions in the PDF.

Chapter Sections (PDF page)
Specifications Processor (3-4), Memory (5-6), Disk Storage (7), I/O Interfaces (8-12), I/O Devices (13), Sound and Video (14), Electrical (15-16), Physical (17), Environmental (18)
Troubleshooting General (20), Symptom Charts: error chords, system, video, floppy drive, hard drive, peripherals, miscellaneous, CD-ROM drive (21-37)
Take Apart Cover (39), Floppy Drive (40), Hard Drive (42), CD-ROM Drive (44), Logic Board (47), Power Supply (53), Speaker (58), Rear Cover (60)
Upgrades Expansion Cards (64), CD-ROM Upgrade (66), Power Macintosh Upgrade (72), Power Macintosh 8500 Upgrade (73)
Additional Procedures Battery Verification (76), Battery Replacement (78), Reset Logic Board (81)
Exploded View Quadra 840AV exploded view with part numbers (86)

What it settles

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  • Power budgets: each SCSI device may draw up to 1.5 A at +5 V and 4.3 A at +12 V continuous, and each NuBus card up to 2.0 A at +5 V, 0.175 A at +12 V and 0.15 A at −12 V (pp. 15-16). The NuBus figures give the units that the Macintosh IIsi Service Source misprints as 175 A and 150 A.
  • Input 100-240 V AC, 50-60 Hz, 200 W continuous (p. 15).
  • RAM: 8 MB standard as one SIMM, expandable to 128 MB; 72-pin, 60 ns, CAS-before-RAS required (p. 5). ROM 2 MB soldered (p. 5).
  • Battery: measure with the cover and logic board removed and replace below 3.2 V (pp. 76-77).
  • Reset Logic Board: whenever a unit fails to power up, remove the battery, press the power-on button with the power supply cable disconnected from the logic board, wait 5 to 10 minutes and refit the battery, before replacing any module (pp. 81-84). The no-power chart lists this as its third step (p. 22).
  • Clicking, chirping or thumping from the supply is diagnosed by removing all NuBus cards and internal drives and refitting them one at a time before the supply is replaced (p. 23).
  • An internal CD-300 is jumpered to SCSI ID 2 (p. 69). The floppy cable must sit in its channel before the CD-ROM drive is refitted (p. 46).
  • Exploded view part numbers include logic board 661-1700, power supply 661-1687 (the same as the Quadra 800), CD-ROM drive 661-0222, floppy drive 661-0121, tape drive 661-0795, power supply cable 922-0838, SCSI cable 922-0871 and composite video cable 922-0870 (p. 86).

Errors in the manual

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Several specification entries appear to have been carried over from the Quadra 800 volume:

  • It lists "one 68040 processor-direct slot (PDS); 140-pin connector" (p. 11). Apple's Developer Note says the Centris 660AV can take a card on the main processor bus and the Quadra 840AV cannot.
  • Its pixel-depth table (p. 6) gives 16 bits per pixel as the maximum at every size. The Developer Note's Table 2-13 gives up to 32 bits per pixel for graphics on the 840AV.
  • It gives GeoPort telephone I/O at up to 14.4 Kbps (p. 9); the Developer Note gives 9600 bits per second.

See Macintosh Quadra 840AV and Centris 660AV Developer Note.

What it does not contain

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  • No Basics chapter; the volume opens at Specifications.
  • No schematic, board-level parts list or component values. Nothing in it identifies a capacitor on the logic board or in the power supply.
  • No voltage-adjustment procedure and no rail tolerance table.
  • The symptom charts refer to a "SIMMs verification" procedure that is not in this volume.

Pages that cite this document

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Download: Quadra_840av.pdf (842 KB)

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