11 Replies Latest reply: Feb 12, 2012 4:58 AM by iMac J
Suzette Richards Level 1 (0 points)


I've got a 7 year old g5 isight. It is still running tiger. It was working more or less ok until the other day when it was switched off for a while. On booting up and logging in it refused to sleep or log off. I needed to shut it down so I had to use the power button to make it go off. It has started to become more unreliable with software issues eg force quit will freeze the entire desktop, you can only use kill -9 from the terminal to kill of an app that's gone bonkers. The ethernet was also not recognised and I had to use it with wifi (which was ok) I also see the beach ball thing a lot but that's probably FF being rubbish.


On trying to get it to boot up again after it was left off for a couple of days it wouldn't even switch on. I left it plugged into the mains and it randomly started up about 10 minutes after it was left alone. It won't get passed the grey screen with the apple logo. Holding down c to boot from the cd does nothing. The fans are running full pelt but it won't boot from anything. I tried unplugging all usb and firewire devices just leaving the normal keyboard and normal mouse and it is exactly the same. I'm sure I can hear the HD making some kind of noise.


Any ideas? The power light bottom right also goes off before the fans start up and go mental. Does this signify anything?


An install cd is now obviously stuck in the drive. The eject key won't make it come out so how do I get that out if the mac is indeed fatally broken?

iMac, Mac OS X (10.4.11)
  • MGW Level 7 (27,020 points)

    Last things first, when you shut down, hold the mouse key and the CD should pop right out.


    Since it won't start from your install cd, and it doesn't get past the grey screen, your logic board has probably given up the ghost.   Given the age of your machine, it is probably not economic to repair it, but you can try removing the hard drive and putting it in an enclosure to retrieve your data.






  • Suzette Richards Level 1 (0 points)


    Thanks for the info on how to get the cd out.


    Any idea on what fails on these logic boards? Caps or resistors that can be replaced?


    Might try taking it to bits and seeing if there's anything obviously fried as it is dead and I can't kill it much more.


    I have online backup so that should have most of the data. Wish I'd copied off my photos the other day as well as the music though as there is tons to download!!


    It's like losing a cherished pet

  • MGW Level 7 (27,020 points)

    You can check for oozing or swollen caps.  They can be replaced with some difficulty because the wires attaching them are very delicate and you have to be a dab hand at soldering.  Best thing would be to take the hdd out and either put it in a bare dock or an enclosure, you can get your photos off that way (unless, of course, the hdd is dead as well).


    I know how you feel, my MBA is in for nuturing, hopefull it will respond well.





  • Suzette Richards Level 1 (0 points)


    Got the cd out anyway   Tried the pram reset again, for an extra bong, but still nothing. Oh well. Will be looking up how to get them to bits. Keep me occupied tomorrow!

  • iMac J Level 1 (0 points)

    Strangest thing happened to me too on Christmas Day. We got a new iMac for Christmas and I decided to clean up the old G5 for Mom. I did a normal shutdown, unplugged and simply moved it aside. later when I went to restart it....nothing. I don't have any swollen caps, none popped..... Been all over the forums and google and noting has worked. I did get a hold of another power supply, including the AC input socket assembly, (which btw was upside down orientation from mine). When I replaced it I still had the same issue. There was no voltage on the DC output side of the supply, AC input measured fine.


    I thought the power supply was a dud since I got it from e-Bay. I completely disassembled the entire iMac  looking for clues or bad connections, cleaned all the fans, etc. Eventually it just started on the click of the power button on what was the millionth attempt. I also checked the power switch with an ohm meter and it tested fine. After 3-days of continuously being on it finally shut down on its own again.


    During the time it was on I reset the PRAM, tried the recommended procedure for resetting the SMU and even changed the Li-ion battery. I started knocking on the plastic housing of the iMac and clicking the button because it really seems to be an intermittent connection. and Viola! it starts every time I do it.


    The difficulty is those logic board connections are so small it's very hard to tell is one is not connecting properly and I need smaller test leads to ohm things out.


    I have an iMac 20 inch iSight G5 7 years old, same age as yours. They are very difficult to disassemble and test because the monitor has to come off to get to the electronics. Mine does not have the removable back. I believe there were different versions.


    If you can, try to reseat any connections you find inside, specifically those on the Logic Board. You may just get lucky!

    If I have anymore success I will be sure to post back. It has become a quest at this point. I always loved this particular iMac and eventually I will get it fixed if it can be done without major bucks.



  • Suzette Richards Level 1 (0 points)

    It must just be switching off the older ones that upsets them. I think I had a problem with it before but I'd probably forgotten. Vowed never to unplug it from the mains but I did..


    On the upside Apple were doing a finance promotion so I bought a new imac. It's fantastic. I can open up loads of things without having to shut down something else first and it is so quiet as the fans aren't always going at full speed  

  • MGW Level 7 (27,020 points)

    Lovely, it's an ill wind.....  enjoy your new power

  • iMac J Level 1 (0 points)

    Well, I believe I figured it out, or just got lucky. After multiple attempts and reading many a post, I started to re-flow a bunch of the solder connections. I went over all the solder points for the caps, since they seem to to be the number one cause, although I never had any that bulged or blew out. I also, hit the power button, a few on the power supply in/out, etc.


    For two weeks now I have been able to shut it down, restart, leave it running, and enter/exit sleep mode. The G5 is running like a champ, and just another Apple product I have which continues to stand the test of time. :-)


    I had read a post from someone else who mentioned re-flowing the solder points, worked for him, on or near the graphics chip. I did have to remove the GPU heat sink on the logic board, to get to the caps mounted on the board, just behind it. A weak or cold solder joint will crack over time. I remembered doing the same thing on my Mitsubishi TV, where the solder joints on the conversion ICs were a known cause and the picture would go haywire.


    I just thought I would post my update in an effort to help someone else. I have found many solutions coming here over the years, and just want to pass it along.



  • Smsgt Level 1 (0 points)

    Hi iMac J,

    I recently replaced my old faithful iMac G3 DV SE with a 20" iMac G5 iSight just like yours. I really like it. I upgraded the RAM to 2.5 GB and it flys. It was a refurnished unit and I would like to clean the fans and the interior, while checking for any obvious physical impairments.


    Noticed your post states you've been inside yours, but was difficult. Could you please inform me as to how you disassembled it. My old iMac G3 was a piece of cake, but I don't know where to start on the new one and trying not to damage it in anyway.


    You expertise will be greatly appreciated.



  • WZZZ Level 6 (12,795 points)
  • iMac J Level 1 (0 points)

    Hello Dennis, I 'm more than happy to help and point you in the right direction. Here is the best link I have found for the iMac G5 iSight.




    After reading a number of posts where some folks were able to lie the iMac face down and remove a few screws to pull off the back I couldn't understand why mine didn't come off. It turns out, as just mentioned above, "it's not a piece of cake" is quite true.


    Look things over first, and if something doesn't seem to budge or come apart, go back and read it again. One tip I will give you is that in order to get to the main logic board the screen must be removed. It is also where the CPU fan is located. There are four very tiny connectors from the screen to the invertor board behind it. You will find two on the top left, and two on the bottom left. Be very careful when unplugging them and make sure the iMac is lying down. If you try to do it while it is upright and the screen slips out of your hands, you can break the connectors. In other words, I ALMOST did that. ;-)


    My iMac was long overdue for an internal cleaning and it was the power issue that forced me to go inside. Also, you might want to buy some aluminum tape, the same kind used for heating and AC duct work. Once you start to pull apart the old tape around the monitor screen, it may no longer stick again later. Very few tools are needed though. and I beieve they were listed in the service manual.


    Go SLOW! You may also want to allow more than a day. In the the end, I was able to get mine working great and it was all worth it. Just be very careful with all the tiny connectors, there's little chance of replacing or soldering any that get broken. The link I posted has great controls at the bottom of the screen but you can not download it. Fair enough, I found it to be the best and appreciate the effort of those who posted it.


    Let us know how it all turns out and Good Luck. You'll get it with this guide. or the other.