iMac G5 uncontrolled reboot

DaveTheGrey

macrumors 6502a
Original poster
Dec 28, 2003
613
0
Hi guys, perhaps one of you can help.
I searched the web and several forums but didn't found a solution.

First the specs:
iMac G5, without iSight
768MB of RAM
10.4.7 with all available updates.

This machine isn't used very often. In the maintime I controll it with Remote Desktop.

It started with a "klack" during the boot process (after the grey screen during the blue one)
after the klack the system stops. after a few minutes it starts again to read from the hd and then another "klack". this happens 5 times and takes about 10 minutes.

right after that i rebooted the system but then there were fewer "klacks" until the system booted flawless. (took about 4 reboots)

if i shutdown the iMac complete, the klack things starts again.

if i don't shut down the imac and let it go to sleep, it automatically reboots every 15 Minutes. The whole day long. I don't know if that also happens when i would work with it but i don't think so.

My unsuccessfull repair trys:

- changed the hd
- reinstalled the whole system
- reinstalled the comboupdate
- repaired permissions
- repaired the drive
- option+alt+p+r holding at startup

I think this really sounds bad and is a tricky one, but perhaps one of you can help me... :(

Dave
 

blodwyn

macrumors 65816
Jul 28, 2004
1,148
1
Portland, Oregon
Dave187 said:
Hi guys, perhaps one of you can help.
I searched the web and several forums but didn't found a solution.

First the specs:
iMac G5, without iSight
768MB of RAM
10.4.7 with all available updates.

This machine isn't used very often. In the maintime I controll it with Remote Desktop.

It started with a "klack" during the boot process (after the grey screen during the blue one)
after the klack the system stops. after a few minutes it starts again to read from the hd and then another "klack". this happens 5 times and takes about 10 minutes.

right after that i rebooted the system but then there were fewer "klacks" until the system booted flawless. (took about 4 reboots)

if i shutdown the iMac complete, the klack things starts again.

if i don't shut down the imac and let it go to sleep, it automatically reboots every 15 Minutes. The whole day long. I don't know if that also happens when i would work with it but i don't think so.

My unsuccessfull repair trys:

- changed the hd
- reinstalled the whole system
- reinstalled the comboupdate
- repaired permissions
- repaired the drive
- option+alt+p+r holding at startup

I think this really sounds bad and is a tricky one, but perhaps one of you can help me... :(

Dave
By 'klack' I assume you mean an audible sound? If so this sounds like a hardware problem. Do you notice anything going weird on the screen when the klack happens? If so it could be a power supply or logic board issue. If it's the power supply then it may be covered by Apple's extended repair program for the G5 iMac PSU's. Probably the best thing to do is take it to an Apple store if you have one where you are in Germany and let a genius take a look.
 

DaveTheGrey

macrumors 6502a
Original poster
Dec 28, 2003
613
0
blodwyn said:
By 'klack' I assume you mean an audible sound? If so this sounds like a hardware problem. Do you notice anything going weird on the screen when the klack happens? If so it could be a power supply or logic board issue. If it's the power supply then it may be covered by Apple's extended repair program for the G5 iMac PSU's. Probably the best thing to do is take it to an Apple store if you have one where you are in Germany and let a genius take a look.
Yes it's an audible sound.
Nothing unusual on the screen before after or during the klack.
No Apple Store in Germany. In Europe there is just one, which is located in London...
Is there a chance to get this support from apple germany?

Thanks for the Link and your time!

Dave
 

DaveTheGrey

macrumors 6502a
Original poster
Dec 28, 2003
613
0
update:

it seems sleep mode is the problem.
instead of going to sleep the iMac restarts. Now I know why the restart period was 15 minutes.
even when I trie to put the imac manually to sleep it restarts.
but not like a normal restart. first it goes to sleep normally and in the next second the grey bootscreen appears.

I think I've got to reinstall the whole os...

Dave