View Full Version : no display on iMac G5 (iSight)

Dec 1, 2009, 02:12 PM
Hello all

today I tried to exit the sleep mode in pressing a key(as usual), but it shows no display, and after a few seconds the fans have become noisy.
I have been using my Mac for bout four years (I almost never turn it off) so I wonder if it is coming to his life's end.:mad:

I tried a PRAM reset using the Apple+Alt+P+R keys: I got the second bong but no luck, the display stays black and eventuelly turns off.
I unplug it for a long time, and replug/power on: no luck
I unpluggued all the peripherals (keyboard): same issue, but the power LED blinks/stays off

I'd like to try an SMU reset as mentionned in step 5 of this article:

I removed the memory access cover as per User guide. But then it mentions two rings in the RAM slots and I think they're inside. So I cannot remove the RAM or take off the back cover.

Any ideas on that or on my issue in general?


Dec 1, 2009, 04:07 PM

Does it sound like your machine is working just fine, other than the screen being black? Press the sound keys up and down, etc. If so, take a flashlight and shine it at the screen, look very closely. Do you see a very faint image? If so you just need to replace the display inverter, and you are a very lucky cat indeed. :D


Dec 3, 2009, 01:51 PM
It seems like you said
I hear the bip when pressing the volume key

I am doing a target mode and I'll think I need a quote for the display inverter

Dec 8, 2009, 10:26 AM
just a recap. Target mode has worked : I was able to retrieve my 400GB data. It only took my about 14 hours.
Removing the additional RAM would not help.

I believe that it is the display inverter even if I look very closely it's REALLY black. So now I can think of 2 solutions :

1/ getting my new chrismas present: an iMac 21,5' :)
2/ buying the display inverter on eBay (or selling the parts if I apply solution 1 ) :D

Dec 8, 2009, 10:31 AM
Why not do both? Try to fix the G5 up and then sell it on eBay. If it doesn't work you are out at most the cost of the inverter. If it does, you will get a lot more for a working G5. Its probably time to move on to Intel anyway you cut it.

Dec 13, 2009, 10:28 PM
is there any website that will explain how to open a broken mac? :D

Feb 3, 2010, 02:13 PM
any update?
I bought the display inverter but I don't how to open the iMac.

Feb 3, 2010, 03:01 PM
Look here (http://www.scribd.com/doc/323004/imacg5-17-isight)

Feb 3, 2010, 03:05 PM
ifixit has a guide specifically for the inverter


Feb 4, 2010, 04:10 PM
I've had both iMac's(pre-isight & iSight) and experienced the same problems and more. I had to keep mine on for weeks-months at a time.I would put it to sleep and it would take about 1-2 days to come back on.I took it to a apple repair center and was told the logic board is fried and the power supply was on it's way out also. The capacitor's exploded. VERY common for these particular iMac's. From what I was told you have to replace the Logic Board, and power supply. Logic board is pretty expensive, so you might be better off saving for a new computer.