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rKunda
Sep 19, 2010, 07:13 PM
Our iMac G5 screen just went haywire. I can't explain it, so take a look.

http://dl.dropbox.com/u/776367/Picture%201.png

I tried to run the hardware test from the install disk, but that disk won't seem to read inside the drive (though all other disks seem to). Any help would be totally.... helpful.



btbrossard
Sep 19, 2010, 07:20 PM
Our iMac G5 screen just went haywire. I can't explain it, so take a look.
That looks like a screenshot? If it is (as opposed to a picture of the screen with a camera), I would say the problem lies with the logic board. If a screenshot looked okay on a different computer, I would say the problem is with the display itself.

Any external monitors to connect to?

rKunda
Sep 19, 2010, 07:27 PM
That's a screenshot. But whatever is causing problems is also affecting screenshots (checked it on a different computer), which gives me hope (false hope?) it's not hardware. So you think it's the logic board?

btbrossard
Sep 19, 2010, 09:25 PM
That's a screenshot. But whatever is causing problems is also affecting screenshots (checked it on a different computer), which gives me hope (false hope?) it's not hardware. So you think it's the logic board?
So the screenshot you made still looks messed up on a different computer?

That would point to a problem BEFORE it got to the display itself (logic board, GPU, rats chewing on wires)...

How's your current backup state? If everything isn't backed up right now, I would recommend you go ahead and do that.

Then you can start troubleshooting. Sounds more like a hardware problem, however.

rKunda
Sep 19, 2010, 09:28 PM
Any ideas where to start with troubleshooting?

mgartner0622
Sep 19, 2010, 09:51 PM
Any ideas where to start with troubleshooting?

Just to rule out software issues completley, boot from a Mac OS Install DVD that's compatible with the computer and see if the screen looks the same as it does in that screenshot.
If it does not, it's a software issue; reinstall OS X.
If it does; hardware issue.

666sheep
Sep 20, 2010, 06:07 PM
It's graphics card failing/overheating. If artifacts/picture corruption are present on screenshot - it's certainly it.
Like mgartner0622 said: if you want to ensure about it, boot from Install DVD and see if it will change anything.

Possible fixes:
- if it's overheating: decent dust cleaning of iMacs innards and replace thermal paste on GPU
- if above won't work: only GPU reballing/replacing could help. GPU is soldered on logic board, so you can also replace entire lobo.

MacHamster68
Sep 20, 2010, 08:53 PM
on a iMac g5 with G5 processor (not the intel in the same housing) i would before i do anything just open it up and look inside for the bad caps as they are in most cases the cause of GPU and other problems
it doesnt look like a screen problem as the known screen problem they get are only stripes on screen yours looks very much like a GPU problem

so look for capacitors that are bulging or leaking as thats the most common problem of the iMac g5
replacing the bad caps is easy if you know how to solder , if not the local radio repair guy might help , here in the uk ebay is full now with repair offers for the bad caps in G5 iMac's

here a pic how you can tell if caps are bulged or healthy on a bulged one the top is dome shaped not flat or the whole body looks a bit blown up , leaking is easy to spot too some brownish colored residue on top
http://www.pcstats.com/articleimages/200302/capblown_3.jpg