iMac G4 has a dead screen - any thoughts ?

Discussion in 'PowerPC Macs' started by timmoore46, Jun 6, 2009.

  1. macrumors member

    May 10, 2008
    I'm a hardware engineer but this has got me puzzled !

    It's my partner Judy's most prozed possesion a Dome with a screen stickout of the top iMac.

    After 6 years of faithful service the screen went dead.

    So I up-ended it to take the bottom plate off and lo the next plate had 4 security screws and eerrrr.....I've no idea which bit comes off next !

    Is there an usual fix for dead screens ?

    Or indeed a way of getting into it ?

    Any thoughts very very welcome !


  2. macrumors regular

    Mar 16, 2009
    In A House, Ontario, Canada
    Could just be a wire disconnection. Can you hear the fans? When you turn it on, do you hear chimes? Try booting with the Tiger or Leopard whatever you use Disc. If that doesn't work, your screwed.
  3. thread starter macrumors member

    May 10, 2008
    Seems to come up fine ! I think the innards are all working fine.

    Can not check the loose wire or duff connector because I can't get into it !

    Hence the cry for help !

    Many thanks for responding.

    : )

  4. thread starter macrumors member

    May 10, 2008

    Half of the answer is here is here:-

    Now it splits about an inch up from the base and on my model a left hand twist shears the heat sink goo unless its turned to rock. This means if force is used the motherboard cracks !

    The motherboard is attached to the base plate,

    The CD/DVD Drive, Hard disc and fan are attached to the Dome.

    I'm stuck at this point !

    I'm still unsure if I can find a solution once I've overcome the bonded heat sink snag.


  5. macrumors regular


    Dec 8, 2008
    just throwing this out there... but it may need a new inverter for the lcd, those are pretty cheap and there are directions online on how to replace it.
  6. thread starter macrumors member

    May 10, 2008
    This looks like the iMac G4 Service manual all 153 pages of it !

    Here is the link:

    Many thanks for the tips !


  7. thread starter macrumors member

    May 10, 2008

    With the aid of a strong torch, I can just see ikons and even opened Finder ! So it looks like the Inverter,

    so now I need to find a source in the UK for them, locate the position of the Inverter in the iMac G4.

    Is it in the screen ?

    And get the thermal paste into the heat pipe interfaces ! Gulp as one of them is cemented on still !

    Any thoughts very very welcome !

    Brilliant tip - many thanks ! - Spot on !


  8. thread starter macrumors member

    May 10, 2008

    There seem to be 3 clock sppeds for the domed iMac G4 17" .

    The one I'm trying to fix has has a 1Ghz clock and is 6 + years old.

    Part numbers as as I can tell are:-

    750Mhz? tba

    1 Ghz needs Part number 922-5298

    1,25? Ghz tba

    They are available in the USA but in the UK they seem to be out of stock.


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