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Recapping a (hopeless?) PowerMac 7100
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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Posted by: sulley86 on 2025-01-22 06:01:34
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.


View attachment 82566View attachment 82567View attachment 82568
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


Posted by: imactheknife on 2025-03-02 10:46:21
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)


Posted by: mitchW on 2025-03-02 12:09:43
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?

Posted by: cluster_fsck on 2025-06-22 06:52:06
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


Posted by: imactheknife on 2025-06-22 07:00:21
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.


Posted by: Franklinstein on 2025-06-22 11:06:39
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.

Posted by: cluster_fsck on 2025-06-23 14:19:15
is it worth it for a regular 7100?

Posted by: testdriver on 2025-09-26 15:32:01
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.


Posted by: sulley86 on 2025-09-28 09:34:55
Rare is relative as to how much is being offered too high then trashed

Posted by: testdriver on 2025-09-28 15:16:35
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.


Posted by: Unknown_K on 2025-09-28 16:19:03
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


Posted by: testdriver on 2025-09-28 16:47:15
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.


Posted by: cluster_fsck on 2025-09-28 16:50:12
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

Posted by: testdriver on 2025-09-28 16:52:10