iMac G5 not working. Need help troubleshooting.

Discussion in 'PowerPC Macs' started by deaathleopards, Apr 29, 2009.

  1. deaathleopards macrumors member

    Joined:
    Apr 17, 2009
    #1
    Hey! My friend's iMac G5 broke. They gave it to me to look at. The serial number was in the range of a defect apple has recognized (can be seen at http://tinyurl.com/c8pjk7) and had a loud fan and was getting scrambled video/very erratic behavior so, I gave it back to them so they could take it to the apple repair centre. After getting a quote they decided it was too expensive and offered the broken mac to me. Now when I try to boot it, I get the chime, but the screen does not turn on and the fan is LOUD. The system then goes into standby mode and, if I try to bring it out of standby it just crashes. I can however target disc mode and see the hard disc.

    Any help would be really appreciated! Thanks! :)
     
  2. vw1300 macrumors newbie

    Joined:
    Dec 31, 2008
    #2
    As a soon former iMac G5 owner, I can say that when this happened to ours (several times) the Apple Store diagnosed it as a bad motherboard. Last month, when they fixed it yet again, they told me that the extended warranty program (as well as replacement program) had ended, and were only fixing mine because it keeps breaking before their 90-day repair warranty expires.

    My advice - sell it for parts, it's worth between $120 and $150, at least on ebay. I put mine on the local Craigslist for $135 and got a good response. Hopefully it will be sold by tomorrow. I just don't think it's worth messing around with a Power PC mac since used intel mac minis and monitors are so cheap now.
     
  3. MTI macrumors 65816

    Joined:
    Feb 17, 2009
    Location:
    Scottsdale, AZ
    #3
    Pop it open (easier than opening an Intel iMac) and do a visual check for bulging or leaking capacitors. If you find them . . . A whole set of caps for the G5 iMac costs less than $20 . . . then decide if your soldering skills are up to snuff or if you want someone more experienced, like a tv/radio repair shop, to handle the hot work.
     
  4. three macrumors 6502a

    three

    Joined:
    Jan 22, 2008
    Location:
    Washington State
    #4
    iMac G5's are notorious for these problems, I'd recommend selling it for parts and buying a newer iMac.
     
  5. spencecb macrumors 6502a

    spencecb

    Joined:
    Nov 20, 2003
    #5
    This happened to mine as well, though they told me it was actually related to the video card. Mine was the first generation iMac G5, but by the time they had replaced the motherboard twice (had to replace the whole thing, since the video card was part of the motherboard) they decided to just give me a new iMac, and I ended up much better off, with an iMac G5 iSight, bigger HDD, etc.

    I know none of that helps the OP, but honestly, there isn't anything you can do, short of replacing the motherboard. From what you described, that is exactly what was happening to mine, so I'm sure that is what is wrong with yours.
     
  6. MTI macrumors 65816

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    Feb 17, 2009
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    Scottsdale, AZ
    #6
    $20 and some time with a soldering iron is something that can be done short of buying a logic board (which could also have the bad caps) . . . :rolleyes:
     
  7. spencecb macrumors 6502a

    spencecb

    Joined:
    Nov 20, 2003
    #7
    I guess that's worth a try, but from what the OP discribed, it sounds like a bad video card. I'm no pro, but can that be solved by using a soldering iron?
     
  8. MTI macrumors 65816

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    Feb 17, 2009
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    Scottsdale, AZ
    #8

    While I am not saying your tech support person misled you . . . but was it ever confirmed to be a "video card" issue? That would be an interesting way to describe it since the video controller is built/integrated onto the logic board, so the typical explanation is "logic board failure."

    The bad capacitor issue is such a widely known fault of the early G5 iMac machines, both the logic board and power supply, that there are numerous websites that detail how to 1) diagnose; 2) order the better caps; and 3) how to go about replacing them.

    I have to add that this issue is separate and distinct from the rampant problems with the early Intel iMacs developing vertical lines and killing LCD panels. ;)
     
  9. deaathleopards thread starter macrumors member

    Joined:
    Apr 17, 2009
    #9
    I have no idea how to do any of this; Are there any tutorials/places to buy this stuff - I would try to do it myself but it's kinda the type of thing you don't have second attempts with if you screw up and weld the wrong things together.

    Update: Oops. Not weld. Solder.
     
  10. MTI macrumors 65816

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    Feb 17, 2009
    Location:
    Scottsdale, AZ
    #10
    http://www.jimwarholic.com/2008/07/how-to-repair-apple-imac-g5.php

    The tutorial will give you an idea of what to look for and possibly give you some confidence. However, as I suggested before, if you remove the logic board yourself, buy the caps and then deliver it to a reliable TV/Radio repair shop, they should be able to replace the caps in a short period of time, if not while you wait.
     
  11. gjw4u macrumors 6502

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    Dec 2, 2008
    Location:
    Switzerland
    #11
    OP, I think you would be better off trying to solder about on your iMac, as a bit of welding would wreck it for good.
     
  12. deaathleopards thread starter macrumors member

    Joined:
    Apr 17, 2009
    #12
    oops

    hahahaha, oops. Wrong word. I was thinking of grade 8 when I almost welded metal to my hand. ;)

    I'll solder. http://www.thecapking.com/applg5.html + $5 shipping to australia = awesome. $21 repair for a free mac. Awesome!

    Thanks :D Good idea, I'll probably end up destroying the mac. Safest to take it to a tv repair shop. Thanks!
     
  13. MTI macrumors 65816

    Joined:
    Feb 17, 2009
    Location:
    Scottsdale, AZ
    #13
    I repaired another failed 17" G5 iMac this weekend. The symptoms were constant freezing or shutdowns, howling fans on reboot (running at max), shutdown messages.

    Replaced 8 caps on the logic board with newer ones and it's been running consistently for the past day.

    For those that are considering taking a stab at the job, I strongly recommend that you buy or borrow a 60W iron, the 30-40W units take twice as long to reheat the factory lead free solder.
     
  14. Junkers macrumors newbie

    Joined:
    Jun 30, 2009
    #14
    hi
    I have similar problem with my iMac G5 2ghz, 17 inch, I have check capacitors and they look good (no bulging or leaking)
    still sometimes it freezes, and I have vertical lines on screen

    any suggestion about fixing it?
     
  15. auto123 macrumors member

    auto123

    Joined:
    Jun 25, 2008
    #15
    I've posted the same idea twice.

    but apparently there are some fixes that involve putting a broken motherboard in an oven (that's right, one used for cooking) for about 10 minutes at 450' F. or using a heat gun on the specific part.

    this essentially re solders the whole thing and makes it like new.

    you could give that a shot (I have a dead AMD 939 board getting ready for that within the coming weeks)
     

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