No Boot on Older Mobo

[G_Train]

Hey All.

A mate sent me his Desktop thats stopped working to see if I could work out what the issue is, but I'm coming up short atm. Its an Asus A7N8X-X, with an AMD TBred 2600, 512ram and a Gecube Radeon 9200 256mb.

He said he started it up, it beeped once and just sat there, no image displayed (though there is a signal going to the screen, as it doesn't say "No Signal") and didn't continue to boot. He reset it and it did the same thing, this time with no beep at all. He reset the CMOS, via removing the battery and replacing the jumper, nothing.

When I recieved it, I swapped out the PSU and GPU, still nothing. So I removed everything and powered on just the mobo, same thing.

I can't test the CPU/RAM as I have nothing of the same type, I'm happy to replace the mobo for him as it's so old it would only cost about $40, but I want to be sure thats the problem, any help?