my machine is cursed

[kentuckyser]

Ok I've got this computer that I've been having problems with. It was giving me checksum errors, and going into a reboot cycle when it hit the Windows loading screen. I could never track down the problem. Also, it would randomly not turn on. Meaning, I hit the power button and nothing happened. If I left it alone for a minute, come back...it would power on fine....albeit still not going into Windows.

Now, I replaced the mobo and PSU last night. First try, no power...pressed the power button and NOTHING happens...but the green light on the mobo is on. Disconnect the power cord, make sure everything is in tight...try again...it comes on...boots perfectly...no errors.

So I left it running all night last night, it runs fine. But, I just checked again on the power thing. I unplugged the power cable, turned the PC from it's side to upright and tidied some wires...that's it...reconnected the power cable and push the power button and NOTHING happens...***? Disconnect power cable...take a look inside...baffled...reconnect power cable...try again....it boots. Seriously, is this machine cursed?

[kentuckyser]

Also, the times it wouldn't boot, I tried touching a screwdriver to the prongs on the mobo to see if the power on switch on the case was bad....but that didn't work either.

Keep in mind I was having this same problem with the old PSU and mobo. There are no shorts that I can see...I've had this thing apart 100 times now.

What causes a PC to do nothing when the power button is pressed, but work sometimes...sporadically?

[Cricket]

What kind of computer is this? Home built or name brand?

What are the complete system specs?

Have you tried troubleshooting the problem with the motherboard out of the case yet?

Are you sure there is nothing under the motherboard that could be causing a short? Like a stray standoff that should be removed.

Cricket

[kentuckyser]

I built this PC back in May and it's been running fine since about October I would guess.

AMD Dual Core 4200+
ASUS A8N-E
Sonata II/Antec 450w
WD 250gb
ATI FireGL V5000
2 GB Corsair Ram

All optical drives and floppy have been removed due to troubleshooting sake. So it's basically barebones right now. I don't even have any of the USB devices, etc plugged in. Just what's needed for it to run.

I haven't done the out of case deal yet, but I'm positive there are no standoffs or screws that are shorting the board. I've taken out and replaced the motherboard about 500 times (sarcasm) each time looking for anything shorting the mobo among other things.

I've actually had that problem before on another machine I built. A screw was stuck under the mobo...it would power on but wouldn't POST.