Project: Reviving an HP E-Vectra SFF Desktop PC
goughlui.com
goughlui.com
It's worth noting he didn't mention checking the caps in the PSU too, or the voltages, because they go bad there too --- and can cause further destruction if they cause the voltages to go far out of range. In particular, a bad cap in the PSU standby feedback loop causing the +5VSB to go up is somewhat common. I've seen it at ~6, 7, or even close to 10V in one particularly bad instance. That would certainly damage any mobo connected to it. A common symptom of high 5VSB damage is a machine that (possibly intermittently) doesn't stay in standby after being shut down, or turns itself on immediately upon applying power.
I had forgotten that such an old machine had a full-screen BIOS logo
I believe most if not all of the prebuilts from Compaq, Dell, HP, IBM, etc. had that. Mobos sold standalone had the classic BIOS POST screen, but some had a utility to let you create a custom one.