Recapping a (hopeless?) PowerMac 7100

[sulley86]

Just thought I'd share some photos of a PowerMac 7100 logicboard which experienced severe capacitor and battery leakage. The computer was from a lab and seemed to have never been cleaned or maintained. I recapped and cleaned the logicboard and the Mac boots and works flawless now, so there's still hope for those machines, even if the logicboard looks terrible.

 

[imactheknife]

Just thought I'd share some photos of a PowerMac 7100 logicboard which experienced severe capacitor and battery leakage. The computer was from a lab and seemed to have never been cleaned or maintained. I recapped and cleaned the logicboard and the Mac boots and works flawless now, so there's still hope for those machines, even if the logicboard looks terrible.


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I just recapped a 7100 i just picked up and now no signs of life. I have done a ton of macs and only ones i seem to have issues with is the 601 boards. I just did 6100 in the same pick up and it works perfectly thank god

 

[mitchW]

I had to recap a 8100 way back in 2015 when it was locking up/crashing in system.
None of the caps were leaking, but they tested mostly out of tolerance (high ESR)

 

[cluster_fsck]

I have a PM7100/80 that’s running fine, and the motherboard is pretty clean (some dust buildup that I try to blow away) but am concerned about the lifespan of the caps. I have limited experience with soldering and motherboard repair - how much should I worry about my system? I may try to find someone locally who can recap it (if anyone knows of someplace in the greater Boston, MA please let me know) but if I wanted to view a tutorial is it best just to hunt around YouTube or is there a better starting point?

 

[imactheknife]

I have a PM7100/80 that’s running fine, and the motherboard is pretty clean (some dust buildup that I try to blow away) but am concerned about the lifespan of the caps. I have limited experience with soldering and motherboard repair - how much should I worry about my system? I may try to find someone locally who can recap it (if anyone knows of someplace in the greater Boston, MA please let me know) but if I wanted to view a tutorial is it best just to hunt around YouTube or is there a better starting point?

It is important to recap these now, but more importantly is new thermal paste on CPU. Out of 6 boards i have, 2 work. They seem sensitive. Have only had one bad 6100, and have 3 working. Also have an 8100 that turns on then off. Cant figure that one out either

 

[Franklinstein]

As far as thermal paste goes, I definitely second checking it.

One time I pulled the heat sink out of a NuBus Power Mac (I think it was an 8115 but maybe a 7100) and not only was the thermal paste dried out, from the factory it was applied off-center so only half of the CPU die actually had any thermal paste on it at all. If it had been a modern (i.e., G4/P4 or later) system it probably would've burned out ages ago, but this old thing works fine with new goo.

 

[cluster_fsck]

Thanks all for the help. Luckily, there’s a great shop fairly close to me that does recaps and am going to have them handle this job. As much as I’d love to give it a go, I’m going to focus on some simple projects to practice my soldering skills and work my way up.

 

[testdriver]

is it worth it for a regular 7100?

 

[sulley86]

is it worth it for a regular 7100?

In my experience, the beige Power Macs are getting especially rare in Europe, with Apple having only a minimal market share back in the 90s. Would be interesting how many of those are still around in the US?

And if someone could share the approximate costs for a recapping service, that'd be interesting, too.

 

[testdriver]

Rare is relative as to how much is being offered too high then trashed

 

[Unknown_K]

1995,6,7 Apple sales were really bad, so the volume of machines made was probably lower than earlier models.

I have a couple 7100's and while the form factor isn't my favorite they are not bad machines comparable to the IIci and Q700 form factor people love. Most people get a PDS video card, so they don't have to deal with that funky audio/video connector. The PCI powermacs that came after were much more expandable so many collectors skip the early PPC 6100/7100/8100 models.

 

[testdriver]

The best thing is it has the same dimensions of say a centris 650 and fits in a ikea kallax

Pci macs abandoned this narrow for factor

 

[cluster_fsck]

is it worth it for a regular 7100?

I don’t know if it’s necessary, but I get good use out of my 7100 as a development machine. The PDS card for video definitely makes usability easier and if you ditch the floppy drive there’s room for the OG hard drive and a BlueSCSI, or similar, depending on your setup.

 

[testdriver]

I need to order the biggest kallax before i can move the 7100 models to the kallax… i may sell the doubles and get the 6100 range more sooner than later