G5 won't start up – has power light but no 'bong' noise??

The other day I left my computer on sleep for a couple of hours, when I returned it didn't come out of sleep so I held the power button down to turn it off. I restarted it but although the fans came on and the light near the power button came on it didn't do the normal 'bong' start up noise and nothing came up on the monitor.

I eventually took all the external cables out including keyboard and monitor etc and started it up on it's own and it eventually came back on as normal, I plugged everything back in and used it without any issues. Unfortunately I went to turn it on last night and I had the same problem although this time my previous success method of starting it up on it's own didn't work.

I've tried pressing the SMU reset button inside the casing but that didn't seem to work either.

Has anyone else come across this problem and is there anything else I can try before sending it off to be fixed?

Cheers

C

It's difficult to try to isolate what could be wrong. There's a possibility that the power supply is defective since it seemed to start when you removed the external loads.

You can try removing the hard drive and see if it will boot from your install DVD. Also, if you have other cards installed in the machine, remove them to see if it will boot. Don't remove the graphic card as that's needed. If none of that works, it may be time to take it on in.

If you get it going again... Turn Off Sleep. The older your G5 gets this is the problem it faces.
I never use sleep mode on any thing.