Powermac G4 FW800 early 2003 boot problems

[jasperino]

The problem: G4 FW800 refuses to boot. Pressing the power button produces the following results:

The power-on button is illuminated, but remains illuminated only for a few seconds, then stays off.
No Chime.
In approximately 10 seconds the Cooling Fan comes on and remains on.
There is no output to the monitor.

This G4 was working as expected prior to being shipped. Thus, something in the shipping process has been damaged, but this something has not been identified.

The following have been done to attempt to identify this problem:

Depressing the C key during attempted boot yields no response. Same response as given above.
Depressing opt + command + p + r makes no difference, with subsequent reboot.

PCI boards have been removed, and the four HDDs and the two optical drives have been disconnected. One time, even the keyboard was disconnected.
PMU has been reset according to the instructions found in the G4 FW800 service manual.

The 3.6V Lithium battery was verified to be properly positioned. Later it was even replaced.

All original RAM was removed and replaced with one 512Mb module known to be functional.


No change in the boot response with any of these actions.

I would be most exceptionally appreciative in any suggestions!

 

[Cory Cooper]

Hello,

Normally, that is a loose connection of exhausted PRAM battery, but you have addressed both of those. It could be a failed video card - happened In my old QuickSilver 2002. Next would be either a failing power supply, the CPU(s) is/are loose, or logic board is failing.

Is it chiming or giving any beeps? If it doesn't chime at all, and you get no video, it sounds like a hardware issue. Tough to diagnose it without having hands-on though.

Honestly, my first guess would be the power supply, which ultimately caused me to retire my QuickSilver 2002.

C