powermac g5 2Ghz only boots in safe mode

fribble

Registered
I have a late 2004 G5 dual powermac 2Ghz with 2Gb RAM and 20' cinema display. Just recently it shut down without warning and now the only way I can get it to boot is by using safe boot mode. If I don't do this then:
the light comes on
it chimes normally
grey screen appears for 15 seconds
machine powers off
light goes off

In safe boot mode the grey screen appears after the chime and the fans begin to roar - suddenly they die down and the blue login screen appears. After that I can use the machine and leave it on for days, but I can't get it to boot normally.

What have I tried:
almost everything I can think of, starting with zapping the PRAM, resetting the PMMU (only done this once); replaced the battery, done the hardware test (2.2.4) which took over 70 minutes and the fans roared the whole time (and everything passed); reinstalled 10.4 (archive and restore), then used the combo updater to take me to 10.4.9; reset the vram in open firmware.

Now I'm going slightly barmy. I've been using and managing macs since 1986 (mac plus, 1Mb of RAM - those were the days!) and never seen anything like this. Now i'm just about to sacrifice a chicken.

But before I do that has anyone any ideas?
Thanks

Howard
 
Back
Top