Should go without saying, but have the motherboards in these systems been recapped before? If not, that may well be the cause, since almost all Shuttle PCs suffered from this problem at one point or another. Pictures of the two system's motherboards would be nice to see, just in case. The Shuttle PSUs were also known for developing bad caps too, but not as often... and you probably ruled that out on both systems if you tested them with a known good brand PSU.

I'm terrible at soldering, and will probably ruin the board worse than it is right now if it turns out to be bad capacitors. I am the original owner of both XPCs, and at least as of right now both PSUs seem to be great. I haven't opened them though, so who knows what they are really like inside. I figured if the PSU was bad I could rule that out with a modern 1000W PSU that should easily handle these old systems.

I'll need to get some more time to inspect the capacitors on the SN95G5 as right now I'm already in bed.

Well, post some pictures of the motherboards if you like. I've seen quite a few of these. OST was a popular choice of caps on those, and the RLP series failed a lot.

Here are some terrible photos I have while it is re-installing winxp from a usb cd onto the 2TB drive now attached to a PCI Sil3114 card.

The caps next to the inductor look bulgy.

And yes, RoHS compliant boards can be a PITA when one doesn't have enough soldering skills. Applying fresh lead-based solder can help.

Tried to take some more photos with it disconnected.

I think these are the ones you are referring to?

reukiodo wrote on 2025-01-15, 07:52:

I think these are the ones you are referring to?

Yes indeed.

reukiodo wrote on 2025-01-15, 07:52:

I think these are the ones you are referring to?

The circled ones should be replaced as soon as possible, but maybe 🤔 even others of the same, although looking good visually, they may not be if verified, clearly you must have an instrument that measures both the capacity and the ESR, the latter in particular could be very high, for removal and replacement, first get quality capacitors, with the same specifications, then if you are not familiar with these jobs, look for someone who does the work for you, and above all has experience with these jobs.

Oh yeah, confirmed you have the bad caps... and mostly OST's like, like I anticipated.

The circled ones here for sure:
download/file.php?id=209996&mode=view

The two in the lower right side of the screen:
download/file.php?id=209991&mode=view

... and probably more that we can't see.

No point in continuing with the OS install. It's just going to get worse as these caps are used further. Need to recap it at this point. You can start by taking out the motherboard and making a note of all of the capacitors: brand (most will be OST, it seems), series (RLX, RLS, RLP, etc.), capacitance (uF rating), voltage (V), diamter (in mm... i.e. 6.3, 8, 10 mm), and height (optional - only needed where the height of the caps is critical for physical clearance).

Depending on where you are in the world, I could suggest where to find caps. In NA (USA/Canada), Digikey and Mouser would be good reliable sources. For the rest of the world, it varies. Some eBay sellers have good NOS (new old stock) caps that should work too... but be careful with places like eBay, and especially Amazon and AliExpress - those are known places to get bad counterfeit caps.