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Thread: MDD (Mirror Dual Door) Power Supply-Help!

  1. #1
    Join Date
    Apr 2002
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    Default MDD (Mirror Dual Door) Power Supply-Help!

    Folks-

    Hereís the story. I bought a used MDD Dual 857Mhz, sold to me as having had the power supply replaced and with no USB.

    I got it, ran through all the PMU stuff with a known good battery, with no luck. The machine would power up, fans spinning, power to drives, red LED on the motherboard glowing. But there was no power on chime. The only other response I got was that the power switch light would blink or pulse twice, about every 30 seconds.

    The Service Manual recommended measuring voltage from the power supply. I did so, with the power cord in and the unit switched off, like the manual saysd. According to the Service Manual, the difference between pins 12 and 24 is supposed to be 12+ volts. I get maybe 3 millivolts Ėessentially nothing. Other pins, like the standby/trickle voltages measured ok. Manual says to replace the power supply.

    Iím perfectly willing to follow the manual, especially seeing as I can probably pick up a new power supply for maybe $20 plus shipping on Ebay. Iím just concerned that Iím getting voltage on some pins and not the others. Can anybody confirm that a faulty power supply will produce power on some pins but not others?

    Also (if youíve read this far), supposedly the power supply was replaced with a new quiet power supply. But when I look at the power supply, it says 400 watts. I thought the quiet power supplies were for 360 watts. Can somebody confirm? The part number is ACI1PC36. Itís an AcBel.

    Thanks.

  2. #2
    Join Date
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    Default Yep...

    Power Supplies have multiple outputs, and even today's have microprocessors built into the supply. Very easy to have a lost circuit.

    If you followed the manual for diagnostics, then for sure its at least a bum PSU.. Although, it could have done more damage down the line when it failed (not likely).

  3. #3
    Join Date
    Aug 2000
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    Concord, CA
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    Default

    The original PS was 400W. My GigaMDD still has the 400W installed altho I took Apple up on their offer for a 360W for the price of shipping. That is a backup if I ever need it.

    SmallDog has MDD mostly refurbed parts. Go here http://www.smalldog.com/category/x/x...Parts/wag10030 and search Mirror Door. They have the 360W PS for $109 and the whole quiet kit for $149. k

  4. #4
    Join Date
    Nov 2004
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    Germany
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    Default

    I can confirm this, original PSU was 400W relacement was 360W the Kit includes a 120mm Papst fan.

    Regards

    Nicolas

  5. #5
    Join Date
    Mar 2001
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    Virginia... where one Democrat CAN make a difference
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    Default

    Check out this thread

    I had an MDD with the same issues as you do and Mr Greentree fixed it right up for me.


    he said this
    Remove ram. remove power cord. remove battery. Reset cuda/ PMU, push pwr button. insert pwr cord and boot yes without ram if you get a beep then ur back in business. put ram back in. if not as above but press pwr and cuda together. have had this issue with a good few G4's and this always fixes them. if not. then leave overnight with pwr out. battery and ram out and when you come in in the morning press pwr button on front one last time. then pwr up.

    Goodluck
    Damien,

  6. #6
    Join Date
    Apr 2002
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    Washington, DC, USA
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    Default I'll try it

    Thanks for the info.

    I'll try the no RAM trick - although my symptoms are a little different from yours...

    Does ANYBODY know if the pins 12 and 24 actually do measure 12 volts with the Duallie plugged in but unpowered? If they do, then mine doesn't work....

    Thanks.

  7. #7
    Join Date
    Mar 2005
    Posts
    9

    Default

    I have a similar problem: see this thread
    When I mesure the voltage between pin12 an pin24, I get:
    1. Nothing (0) when the power cord is pluged in but without turning on the computer.
    2. +12V when the computer is turned on.

    But as my computer doesn't work too, I can't assure you that this is normal.

  8. #8
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    Default I am confused..

    You have the technical repair manual, it tells you whether or not you have a bad supply. There are specific steps to take to determine whether a PSU works. What more do you want from the forum?

    This is like questioning a "map".

  9. #9
    Join Date
    Mar 2005
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    9

    Default sometimes the map can be wrong

    @rguising:
    sometimes the map can be wrong, vorkosigan1's question is logical, so you could be more polite ...
    and even Apple does sometimes mistakes

    @vorkosigan1:
    now I know for sure: you shouldn't get any reading with the G4 plugged in but unpowered between pin 12 and pin 24. So your PSU is probably OK.
    Hier is the updated version of the service manual
    (Section Troubleshooting->General Info->PS Verification): hier
    and specially for rguising, so that he can check the differencies, the old version is hier.

  10. #10
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    Default Not trying to be unpolite here

    My only point was:

    The going rate for an MDD power supply is about $50. This is for a $1000 machine. It seems foolish not to buy one, and sell it if it doesnt do the job.

    My experience with multiple MDD's is that their Logic Boards as well as the CPU modules are prone to failure. I cannot speak to a failure of a PSU.
    Last edited by rguising; 03-02-2005 at 07:40 AM. Reason: change of text

  11. #11
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