I recently bought a replacement PSU for my Aptiva from overseas. At first it worked fine but over the last couple of months it has deteriorated to this: voltage LEDs on the diagnostics card power on briefly, then it powers down again. Very rarely it powers on fully, but then dies after a minute tops.

https://photos.app.goo.gl/8r6TvWZZgJcgrPpCA

Its one of those "smart" AT PSUs that IBM used before ATX standardized power management, so when it's working it can power up and down sort of like an ATX PSU. That's also why it has a button for powering on, not a switch. It's pretty rare in these parts, which is why I got it of Ebay in the US.

Anyway, any thoughts? I didn't pop the hood yet, but perhaps this is what a developing cap issue looks like? 🙄