Weird power issue/ mobo ? x-post

My system is several years old, a P4 3.4 on an ASUS P4c 800e mobo, Antec 550W PSU,etc.

Roughly 6 months ago, I had several occasions, that after shutting down my computer, nothing would happen when I pushed the front momentary switch the next time I tried to turn it on.

I found that it would start, if I turned the rear main off, then back on, then retry the momentary switch.

Roughly 3 months ago, after shutting down normally using the menu, after ~30 secs or so, the case fans, and CPU fan would come back on, but not in a reboot. There'd be no HD activity, and once again, the front switch, even when held in for "ever" would not shut the fans off. I had to turn off the rear main. Turning the rear switch back on, all of the fans would come back on again, but the front switch would do nothing to get a boot started or to shut things off.

I found that if I held the momentary switch held in, while I turned on the rear main, I could get a normal power up/boot, but I had to power down by using "stand-by", instead of "shut down" to avoid what I detailed above. The front switch would then behave normally on the next power up.

This lasted for maybe 3 months until last week, when I tried to turn my computer on. The front switch did nothing, so I tried what had been working, turn off rear main, hold in the front switch, and turn on the rear main, but nothing happened. I retried about 3 times, then I heard a pop at the rear of the case near the PSU, then absolutely nothing. NO fans, no lights, nothing.

I took the PSU to a shop a block away to have it tested and it was bad. I bought a new supply but as soon as I turned on the rear main, I was back to square one. Case fans, cooling fans spinning and a front switch that does nothing.

I went back to the shop and they said it must be a bad mobo, so I returned the PSU and have been trying to find a replacement board.

But after a lot more reading, I'm thinking it might be a short in the front switch, which I didn't check. It "feels" fine, and sounds normal, but...

Anyone have any other thoughts?

HMmmmmm, My first question when i hear about an old computer going out is.......Do u clean it regularly? Cigarette smoke is the number one cause of computer death in america. jk. Cat hair and dust are also pretty bad.

I need more of an expert here, but ive heard ppl taling about hitting the power pin on the mobo with something metal when not plugged into the case switch to test it.