Editing Macintosh IIvi Troubleshooting

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[[File:Macintosh IIvi (photo).jpg|thumb|right|300px|Macintosh IIvi (All About Apple museum, Wikimedia Commons, CC BY-SA 3.0)]]
Fault-finding for the [[Macintosh IIvi]]. The tables are Apple's symptom charts from the Service Source it shares with the [[Macintosh IIvx]] and Performa 600, with the cures in Apple's order: try the first, check whether the symptom persists, and if a module swap does not cure it, refit the original before moving on.<ref name="ss">Apple Computer, ''Macintosh IIvx, Macintosh IIvi, Performa 600'' Service Source, [[:File:Macintosh iivx.vi.perf 600.pdf]]; see [[Macintosh IIvx/IIvi/Performa 600 Service Source]]. Troubleshooting, PDF pp. 15-24: General p. 15; Video pp. 16-17; Floppy Drive pp. 18-19; Hard Drive p. 20; CD-ROM Drive p. 21; Peripherals pp. 22-24. Battery Verification pp. 68-69.</ref> Apple's cures stop at module level; the known faults follow the charts.

== Power and start-up ==
{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Symptom !! Apple's cures, in order
|-
| Screen completely dark, fan off, LED off || Check the external power cables; remove peripherals; remove the NuBus cards and switch on again (combined cards should not draw more than 45 W); remove the accelerator card; power supply; logic board
|-
| Screen dark, no audio or drive activity, fan and LED on || Remove peripherals; remove NuBus cards; DRAM SIMMs; VRAM SIMMs; power supply; logic board
|}
The machine is switched on from the keyboard's power key, which the 68HC05 microcontroller watches using the power supply's +5 V trickle output; that output is live whenever the machine is plugged in. Shut Down turns the supply off through the same controller.<ref name="dn">Apple Computer, ''Macintosh IIvx Developer Note'' (1992), also covering the IIvi and Performa 600, [[:File:Macintosh IIvx IIvi and Performa 600 Developer Note.pdf]]; see [[Macintosh IIvx IIvi and Performa 600 Developer Note]]. Printed page numbers: video modes and FPU pp. 4-5; RAM p. 9; VRAM p. 10; ADB, clock and PRAM p. 19; soft power p. 20; power supply p. 28; internal SCSI devices and CD-ROM ID pp. 31-32.</ref> A blank screen for some seconds after switching on is normal: RAM is tested and sized before video starts, longer with more RAM fitted.<ref name="dn" />

For the Sad Mac codes of the Macintosh II family, see [[Sad Mac Error Codes#Macintosh II Family (II, IIx, IIcx, IIci, IIfx, IIsi, IIvi, IIvx)|Sad Mac Error Codes]]. Apple's charts for this machine do not list them.

== Video ==
{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Symptom !! Apple's cures, in order
|-
| Dark screen; audio and a drive working, fan and LED on || Monitor brightness; monitor; video cable; VRAM SIMMs; logic board
|-
| Screen bright, audio present, no picture || Monitor; video cable; VRAM SIMMs; logic board
|}
VRAM SIMMs go in identical pairs, 100 ns or faster. Apple warns that VRAM which does not meet its read-transfer timing can leave visible artefacts on the screen. There is no 1-bit mode on Apple's 12-inch RGB monitor.<ref name="dn" />

== Floppy, hard and CD-ROM drives ==
{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Symptom !! Apple's cures, in order
|-
| Floppy drive does not work || Floppy cable; floppy drive; logic board
|-
| Disk ejects and a Mac icon with a blinking X appears || Another disk; floppy cable; floppy drive; logic board
|-
| Disk will not eject || Switch off and hold the mouse button down while switching on; eject manually; floppy cable; floppy drive
|-
| Drive tries to eject but fails || Push the disk fully in; push a straightened paper clip into the hole beside the slot; floppy drive
|-
| Hard drive runs continuously || Turn off virtual memory and see whether it stops; SCSI data cable; hard drive; logic board
|-
| Hard drive does not work || SCSI data cable; SCSI power cable; hard drive; logic board
|-
| CD-ROM drive will not accept a disc || Try another disc; CD-ROM mechanism
|-
| No CD-ROM icon on the desktop || Reinstall the CD software and check the CD-ROM extensions are in the System Folder; reinstall system software; CD-ROM mechanism; power supply; SCSI data cable
|-
| Works with the internal or an external SCSI device, not both || External devices must use different SCSI IDs from internal ones; the hard drive must be terminated and the CD-ROM must not be; external terminator; the external device's SCSI select cable
|}
The logic board's active terminator ends the internal bus when nothing is plugged into the external port. Apple's internal CD-ROM is SCSI ID 3.<ref name="dn" /> See [[Macintosh HDD Maintenance]] and [[Macintosh Floppy Drive Maintenance]].

== Keyboard and mouse ==
{| class="wikitable styled-table" style="width:100%; text-align:left;"
! Symptom !! Apple's cures, in order
|-
| Cursor does not move || Restart; mouse connection; connect the mouse to the computer's ADB port, and replace the keyboard if it then works; mouse; logic board
|-
| Cursor moves, clicking does nothing || Mouse; logic board
|-
| Double-click does not open anything || Remove duplicate System files; clear PRAM (Command-Option-P-R at start-up, before "Welcome to Macintosh"); check keyboard and mouse as above; logic board
|-
| No response from the keyboard || Keyboard connection; keyboard cable; keyboard; logic board
|-
| Beep whenever a key is pressed || Turn off Slow Keys in the Easy Access control panel
|}
The ADB port supplies +5 V on pin 3 through a 1 A fuse.<ref name="dn" />

== Known faults ==
=== Battery ===
Apple's test is on the 10 V DC range; replace the battery below 2.8 V.<ref name="ss" /> Recap-a-Mac's photograph of a IIvi logic board shows the battery holder, BT1, and the area around it destroyed by a leaking cell.<ref name="ram">{{cite web |url=https://recapamac.com.au/macintosh-iivi/ |title=Macintosh IIvi |publisher=Recap-a-Mac |access-date=2026-09-30}} Annotated photograph of logic board 820-0373-A, hosted here as [[:File:Mac IIvi Recap Guide.jpg]]; the IIvi is not "immune from leaky capacitors and exploding batteries".</ref> Remove the battery from a stored machine, and neutralise lithium residue with bicarbonate of soda. See [[Battery Explosion, Capacitor or Corrosion Damage]].

=== Capacitors ===
The logic board has six 47 µF surface-mount electrolytics and two 220 µF axials, which leak with age.<ref name="ram" /> See [[Macintosh IIvi Capacitor Replacement Guide]] and [[Capacitor Failure Symptoms]].

=== No FPU ===
The IIvi has no 68882 as standard, only a socket for one, so software that requires an FPU will not run until one is fitted. Programs are meant to check for it through the Gestalt Manager.<ref name="dn" />

== Related pages ==
* [[Macintosh IIvi]]
* [[Macintosh IIvi General Maintenance]]
* [[Macintosh IIvi Capacitor Replacement Guide]]
* [[Macintosh IIvx Troubleshooting]]
* [[Sad Mac Error Codes]]

== References ==
<references />

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