Computer troubles...

[Th3_uN1Qu3]

Re: Computer troubles...

Bad BIOS would be my first guess, short on CPU VRM would be my second, dead chipset would be the third.

[tom66]

Re: Computer troubles...

No, it only powers up for about 3 seconds and during that time there's no video. There's barely enough time for the CPU fan to start spinning.

It's like one of the very first checks is failing.

[stj]

Re: Computer troubles...

simple test,
if you go into the bios settings - does it stay on?

my one did - it was only when the o.s. started ramping up the system that it doed.

[tom66]

Re: Computer troubles...

i have seen a bad cpu do that.
i think it had a short in a section that is not active at boot.

I'm hoping it's not that. I'd expect CPUs to be quite reliable but I'll need to rule it out...

[stj]

Re: Computer troubles...

i have seen a bad cpu do that.
i think it had a short in a section that is not active at boot.

[tom66]

My home PC is giving me some trouble, it's not booting up properly.

The power cycles on and off continuously. It doesn't show any signs of activity and only turns on for about 3 seconds before turning off for one, then repeats this cycle continuously. I have bench tested the power supply and that seems OK. It stays on when PS ON is held low. I've also scoped the rails on the outputs and they seem reasonable when under normal load, 12V at 12.2V, 5V at 5.09V, 3.3V at 3.37V. I'm thinking it's the motherboard, which is a Gigabyte Z97X-UD3H.

Does anyone have any experience of this issue?

Have done the obvious, like disconnecting all peripherals and drives, all fans, and running with only one stick of RAM. Will try another PSU just in case, also need to reset the CMOS or maybe use the backup BIOS flash on the board (apparently it has two).

Took power supply apart (EVGA NEX650G), no bad capacitors visible.