Power up problem

[TonyMan]

My wife's PC is having problems powering up. It either does nothing or else we see a quick flash of the case lights then nothing. What I have found is if i turn the power off on the back of the case for a few seconds then try the switch in the front of the case it will boot. I built this a few years back. The motherboard is a Gigabyte K8 Triton Series GA-K8NS. It's been a while and I know it has an Athlon 64 CPU. I'm thinking it's a motherboard problem and maybe time to buy her a laptop.

Looking for any thoughts on what it could be or to identify what is causing it.

Thanks

[Train]

I would figure either the power supply is going or the relay in the motherboard which would call a mobo replacement.