View Full Version : G4 - black screen, no drive spin-up

11th November 2005, 01:10 PM
In despair!
Using a G4 733 Mhz with 17" Studio Display. While working with Photoshop the screen suddenly went black. Tried to restart. Chimes ok.
Lights on. Fans on. No discernable disk spin up! Black screen.
Unplugged everything. Waited an hour.
Startup with same result.
Tried starting up with Tiger DVD. No better response.
Tried starting up with Panther CD. No better response.
I'm mystified at the moment.

Is this:
Monitor problem - I doubt it
Video card problem - but why no disk spin up?
RAM problem - no change to RAM for years - chimes okay
Hard Disk problem - why no startup from CD?
Power supply failure - why do fans and lights work?
Logic board failure - Could be: how can I tell?

Any suggestions would be welcome.


Mac Aid
13th November 2005, 11:08 PM
Try reseting the PRAM.

Failing that, try reseting the PMU. To do this, make sure your clock battery is good, disconnect the power from your machine, and momentarily press the PMU reset button on the logic board ( you may need to download a service manual to find this). Wait min 10 seconds, plug the power back in and try again.

Failing that, it could be the power supply, or the logic board.