iMac G5 Screen and Startup Problems!

Mine is doing almost exactly the same thing, and it also froze the first time while the screen saver was on. I suspected a software issue, and have gone so far as to wipe the hard drive (erase, plus zero all blocks w/disk utility), and reinstall the OS fresh and it still does it. The hang occurs just as I get to the blue startup screen, but before the "Loading Mac OS X" box & progress bar shows up. I also get the display glitches from time to time, but not all the time.

The one small bit of relief is that I am able to consistently get the machine to boot completely in safe mode, but not "normally." Any advice on what may be going on here?

To College Kid: try starting up your iMac in safe mode - hold down shift until the "gear" starts rotating under the Apple logo on the startup screen. That was how I was able to get mine started up to get the data off before I wiped the drive.

*I got my imac G5 in October, 2005. I had same problem last year. It ended up having to replace my logic board. Lucky, I had apple care. If not, it will cost $980. Changing logical board will not get your data lost. Don't worry. Now my imac has a yellow vertical line on my screen. Sometimes it appears. Sometimes not. I thought apple computer can last for at least 5 years. However, it seems it's time to shop for a new one. :(*

I think that you are mistaken in your diagnosis, and it is very likely an issue related exclusively to hardware.

If you remove the back of your machine, you can inspect the clusters of electrolytic capacitors on your logic board for evidence of distention, bloating or leakage. Each cluster impacts specific areas of operation on your logic board, including a set which are a part of the video circuitry. You'll likely find, if you have a first generation iMac G5 17 inch or 20 inch model, that this is the cause of the symptoms you see.

While Apple no longer replaces affected logic boards under the terms of a now expired repair extension authorization, it is possible to repair such boards for $ 189.00 plus the cost of shipping. If you are interested in exploring that option, write to the address in my Public Profile for more information.

I had the same problem. Turns out heat was the culprit.

Check out this program, it works really well.
http://homepage.mac.com/holtmann/eidac/software/smcfancontrol2/index.html


I came across it in this discussion
http://discussions.apple.com/thread.jspa?threadID=1313995&start=0&tstart=0

Hope this helps.