G3 iMac "PAV board" "power supply" same thing?

Discussion in 'PowerPC Macs' started by ActionClaw, Mar 25, 2008.

  1. ActionClaw macrumors newbie

    Mar 25, 2008
    Like many others, I have a G3 iMac (specifically, 400mhz iMac DV) that suddenly, mysteriously stopped working.

    It seems a well known problem. My situation ranges from "similar to" to "identical to" these:

    Yes, I've tried the new battery, pmu reset, upside down boot, etc. No luck. Many posts I've read, here and elsewhere, somtimes indicate the culprit to be a bad "PAV board" - other times a bad "power supply". My main question is, is the "PAV board" and "power supply" referencing the same part using different terminology or are these 2 different parts?

    - If these are 2 different parts, which is the one that is most commonly known to go bad on G3 iMacs?

    - I have access to a few tray-load iMacs. I realize many (probably most) parts are not interchangeable between the
    tray- and slot-loaders but might anyone know if the power supply or PAV boards are.

    - On all these malfunctioning PAV boards (or power supplies), is it always/usually the same component that fails?)

    - Thus far, I've not been able to find any but might someone be able to direct me to any available documentation pertaining to step-by-step disassembly instructions to access the power supply, tests/voltage readings to confirm if it is problem, etc?

    (Yes, I realize I need to replace it with a newer Mac. Regardless, I still find this useful and, if possible/practical, would like to repair it.)

    Thanks for any help
  2. Macmaniac macrumors 68040


    The PAV and power supply are the same thing on the iMac.
    The PAV means Power, Analog, Video. So its contained all in one unit.

    One nice thing about the slot load iMacs is that the PAV boards are interchangeable!

    There is one thing you should know, Apple used two different models of CRT Tube, one was LG, one was made by Hon Hai, Apple made some PAV boards which had a switch to "adjust" to the two different models. Others don't have the switch, if the one you pull out does not have a switch don't worry it should work.

    Now here is my advice. Don't do this, it's a really tricky take apart, I have been working on iMac G3s for 4 years and these are one of the most difficult machines to fix short of being a laptop. This is also THE hardest part to replace.

    Here is a link to the complete take apart guide, this includes information on the switch on the PAV board if your model has it.


    If you page through it quickly you will see that its not easy to do, and you will need some tools to discharge the CRT tube!!! This is very important, the PAV is connected with the CRT tube, and MUST be discharged before you separate the two, the steps are shown in the take apart manual. If you don't do this you run the risk of electrical shock which is strong enough to kill you.

    However, if you are feeling adventurous and have several iMacs that you feel like taking apart go for it, but I almost assure you that you will crack, or break something on your first try, its very hard to take apart.

    Sorry if I put a damper on your hopes to take it apart. I learned from a guy who has been doing these machines for years, and he hates doing them cause the PAV is such a pain to get out.

    I hope I have been some help.
  3. blackcwolf101 macrumors newbie

    May 1, 2010

    Hi i was wondering if i could use an alternate power source to the mac g3's PAV?

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