# Power Mac G5 won't boot



## lincolnparkjok (Aug 8, 2010)

Hello all. I'm trying this as a last resort. I'm new to Mac, but a fairly proficient user/troubleshooter of Pcs. I've read hours of forrum posts on the subject of troubleshooting a grey screen/won't boot issue, but everything I've tried hasn't worked. I'm hoping you can help.
The problem is, this Power Mac G5 2.0 dual starts up, chimes, goes to a grey screen with the Apple logo and stops. No spinning wheel, nothing. I've tried Option + boot, it gives me the option to boot from different drives, including the OS install disk, biut when I select any of these, I get the same grey screen.
I have reinstalled the OS numerous times on different hard drives, swapping them out to see if that was the problem, but no change. I have the G5 connected to a different Power Mac G4 via firewire target mode. Using this I've repaired permissions, repaired disks, reformatted and re-partitioned 4 different hard drives, but same thing, it won't boot.
Currently the G5 is started in target mode, and I have the G4 booted from the G5's startup disk. The G4 is running fine from the G5's disk.
I also wanted to try the Apple Hardware Test, but unfortunately, I do not have the original disks that came with this Mac.
Any help and/or suggestions would be greatly appreciated.


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## DeltaMac (Aug 8, 2010)

What is the memory configuration in your G5? Have you tried reseating the RAM? Try using only one pair, identical, installed in the center two slots. Counting the slots 1-8. one pair would go in slots 4 and 5. Or, slots 2 and 3 if your G5 has only 4 memory slots.
Do you have extra PCI cards installed? Try removing those. Reseat the video card while you are in that area.
What version of OS X are you trying to boot with? If you think your hard drive has a good install of OS X, try removing all external devices, except for your keyboard, mouse and display.
Have you tried a different keyboard?
Start up your G4 in target boot mode. Can you boot your G5 selecting the hard drive in the Option-boot screen? Again, what version of OS X is installed on the G4?
Have you tried other versions of OS X?


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## djackmac (Aug 8, 2010)

I've ran into this with a few similar/identical machines and its turned out to be the logic board. But there is still a lot that needs to be ruled out like RAM or perhaps a processor. Just like Delta said verify the RAM is seated correctly. Try each pair individually in proper configurations in all different pairs of slots. Try inspecting/reseating the video card or if the card has a built in fan, make sure it is turning and cooling the card. Then try to boot from the G4s drive with the G4 in TDM to rule out the SATA bus or a bad SATA cable. Try disconnecting the optical and booting. After all this, you may need to get into reseating processors and trying each processor individually.


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## lincolnparkjok (Aug 8, 2010)

Hmmm..interesting. Well, the os that is installed is 10.4.6. I have removed all the RAM, resat it in many paired configurations, and resat the video card. There aren't any external devices, except for my keyboard, mouse and display. I have tried a different keyboard. I have tried booting the G4 with the G5 in target mode..but I didn't think to try it the other way 'round! I'll give that a try. Also, am running a Apple Service Diagnostic 2.5.8 cd as we speak. So I'll give it a whirl and let u know what I find. (Hope it's not the logic board..  :-(


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## lincolnparkjok (Aug 8, 2010)

Update. The ASD cd reported everything fine in the EFI mode, gonna run it in OS mode now...we'll see what happens. In the interim though, I did try booting the G5 from the G4, but unfortunately all I get is the same grey screen.  grrr


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## djackmac (Aug 8, 2010)

Where and how did you get a copy of ASD2.5.8?


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## lincolnparkjok (Aug 9, 2010)

There are links (paid) to download and burn a .dmg of ASD. Don't reeneber where, but it was like $14.95 or something.


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## DeltaMac (Aug 9, 2010)

Interesting for software that is not for sale....
As djackmac can also tell you, the Apple Service Diagnostics are provided by Apple only to Apple authorized service providers, and are proprietary diagnostics not meant to be released to the public.
Does your G5 actually boot to the OS partition on the ASD disk? If there is a hardware problem preventing booting to OS X, that should fail, too...


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## lincolnparkjok (Aug 10, 2010)

NO, it only boots in EFI mode, not OS mode.


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## Satcomer (Aug 10, 2010)

Can you boot into Single-User mode? If you can check the hard disk with fsck command in the Apple document Resolve startup issues and perform disk maintenance with Disk Utility and fsck.


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