I Have a G5 iMac from 2003 running Mac OS X 10.5.8 When I turn it on there is no picture on the screen and the fan kicks in at full blast. I opened the back panel and the insides look almost brand new with not a speck of dust. The capacitors look great too. I tried resetting the PRAM and The PMU, but no luck. Do you think a new PRAM battery will solve my proble?
iMac, Mac OS X (10.5.8)
The old issue of a dead PRAM battery resulting in no video affected much older Macs than the G5s (typically 4XX-6XX series Performas and 5XXX-6XXX series and similar early PowerMacs.). However, it's is something cheap to try as you already know how to access the battery.
You should have a Mini VGA port for an external display. An external monitor is a good diagnostic tool. If the video artifacts repeat on the external, your problem is likely a failure of the logic board video hardware and, given the age of the computer, not economically viable to fix. If the image on the external is normal, then the problem is likely a defect in the display itself or its cabling. The later is potentially the cheaper fix although parts for those are getting very hard to find.
Check your serial number. If it begins with "W8" it is from a factory that shipped thousands of G5 iMacs and G4 Powerbooks with defective displays.
1) Try a safe boot.
Shutdown your machine. Hold down the shift key. Poweron. Wait awhile; wait awhile while you harddrive
is being checked.
http://support.apple.com/kb/ht1455
2) Another way to correct filesystem problems is into single use mode.
This page will tell you how to get into single user mode.
http://support.apple.com/kb/HT1492
Basically, you hold down the command + s key then powering on your machine. The command key
has a little apple symbol on the lower left. It is between the alt/option key and the space bar.
Will a new PRAM battery fix my iMac?
