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68kMacx86

A Mac IICI WIth no ROM SIMM, BAD PSU, BAD FLOPPY

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I was told that the trickle charge on the PSU was not present therefor the computer would only turn on once then need unplugging.  I noticed the ROM SIMM is missing so im going to need to buy one from BMOW and i noticed floppy drive is stuck so another emu it is.  any ideas on fixing the PSU?

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The IIci has onboard ROMs. The SIMM is optional.

When a IIci does not power on you usually have two sources for that error nowadays.

First you will have to recap the logicboard. The power-on circuit relies on a feedback circuit that involves caps and also those exact caps will do further damage to logic ICs in the startup circuit if they leak.

If your Mac starts up normally afterwards you are good to go. If not you have to check the power supply as well. There is a weak spot in them as well. Don’t nail me down on the exact procedure but you are on the right track with the 5V trickle voltage that dwindles down over time while the machine is plugged into a wall outlet and isn’t enough in the end to trigger the feedback circuit on the logicboard.

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That corrosion isn't all that bad, use vinegar to neutralize it then scrub and rinse with toothbrush+IPA

 

As to the PSU, check the low voltage side's caps for leakage and/or dryness (test out of circuit)

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I can probably help you with this board if you need it. I just got a spare IIci from the junk shop, but I haven't had time to look at the logic board yet. I can replace caps and clean boards though, anyways.

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I am going to need to get a II series psu.  one of mine in a P600 blew up the other evening and so i stole the IIci's power supply.  I have the case for it, i might just order a quadra 700 motherboard and stick it in.

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Q700 board will need you to open up some new spaces on the back of the case to accommodate for some new ports and perhaps some things that changed places.

 

I would only do it if you can find a Q700 (or 650) board for a lot less than an entire Quadra or Performa as discussed the other day would cost, especially given that you're already planning on needing to replace or repair the diskette drive.

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Cory5412, I am able to procure a Q700 board for about $30.  Unfortunately the school does not have any Macintosh II stuff save for a boat load of IIx machines.  I would be heavily interested in them, were not for the fact that all of them have serious water damage and rust from being underwater in a flood in the late 90s.  they were put in this particular warehouse in 1995 and forgotten until recently when the school decided they need this space for other things.  seriously every inch of these machines is covered in rust where there was metal.. the plastics are disgusting.  if you can give me one reason to not chuck them.... i'll see what i can do but they are about to be chucked.

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45 minutes ago, 68kMacx86 said:

seriously every inch of these machines is covered in rust where there was metal.. the plastics are disgusting.  if you can give me one reason to not chuck them.... i'll see what i can do but they are about to be chucked.

Plastics may be cleanable.  If I recall, the II series had better plastics than later models that now fall apart if you breathe too close to them.

 

If the rust is just surface rust, those metal parts may be salvageable.

 

The electronics would be of greater concern.  Sometimes they might clean up well and be restorable.  Other times, no.  Mouse urine is generally more damaging than water.  Oy, mice.

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Yeah, you know what lengths we'd go to to salvage a Mac IIx. If it's as bad as you say then it's possible it's not worth it.

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If the price is right for you given they're water damaged, I'd say go for one of the IIx's. They may not be particularly fast, especially compared to the later II-series machines, but IMO they're still pretty fun to mess with (6 NuBus slots!) and restoring one may be a fun project.

 

$30 to upgrade a IIci to a Q700 is really good compared to the prices for Quadras on eBay, but as Cory5412 said, you'll have to modify the back of the case for it to fit.

Edited by AwkwardPotato

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