Desktops: Computer died very suddenly, won't resucitate

Computer died very suddenly, won't resucitate

My dad was using his computer last night when it just went blank. The peripherals were still working, including the monitor, but the CPU was dead.

the power supply is firmly attached. Nobody has been in the case in the past 3 months. Resetting the power didn't help. It stays very firmly off. No lights. No boot menu.

We've had this computer approximately four years, but it was cutting edge when we bought it and it has shown no signs of wearing down over time - we're not power users.

The only thing we've had to replace was the optical drive. That was several months ago, and there were no issues.

It's got an Athlon 64 2800 processor, a Maxtor HD, 510 GB RAM. I can dig up the exact specs for everything if it's necessary.

But I've heard that a single damaged component can shut down an otherwise perfect system. If it's something like that, how can I isolate and fix the issue?

Thanks!