I brought up the system in safe mode and screen noise was still happening.

The diagnostics I ran wasn't AHT, it was a separate CD I had gotten called turbo tech tools or something. think it came with my system but its pretty useless cause its finding no problems.

My G5 is PowerPC based so I see that the way to run AHT is by holding either alt or ctl with install CD1 in on startup.
however, this isn't working for me.

not sure if its cause I don't have my original kbd or cause i'm holding ctl & option? I have a usb keyboard. Anyone know how to determine which key I should be hitting, also is it possible to do this with non-apple USB keyboard.
The kbd I had been using was a wireless usb, but i put a cabled usb on for now thinking this was better?

when trying to boot into AHT, the System is coming up in regular mode. While leaving it up looking for more information about AHT and keyboards, etc I hear a faint click & the computer immediately powers off. This has happened 4 times already and it happens after the system is up for about 15 minutes.

HELP!
thanks,
Joe