Mac Pro: Turns on and Then Turns Off

Discussion in 'Mac Pro' started by arobertson545, Oct 29, 2011.

  1. macrumors newbie

    Feb 24, 2011
    I have a Mac Pro 1,1 from 2006 and I am having a start up problem. When I start it up for the first time in the day (usually in the morning) the power light glows and then the computers shuts off, this then repeats. After it has done this about 5-10 times the computer successfully starts up. Once it has started up, it can be shut down and restarted without a problem and all the hardware works.

    Any suggestions?
  2. macrumors regular


    Oct 19, 2007
    Nambucca Heads Australia
    You have a failing power supply. Pretty common in the 2006 model Mac Pro 1.1.
  3. macrumors G4

    May 6, 2008
    I'd say PSU as well.

    Given it's age and description, the main supply capacitors are probably leaking/bulging, and don't work properly until they're up to temp.

    If the OP is handy with a soldering iron and knows enough about electricity (particularly safety), they could replace them if a replacement PSU isn't available, or costs an arm + leg.
  4. thread starter macrumors newbie

    Feb 24, 2011
    I'll try and find a new PSU. Is it relatively easy to fit?
  5. macrumors G4

    May 6, 2008
    It's not too difficult IMO. :)

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