Help! Macpro Intel Core switches off

Discussion in 'Mac Pro' started by Tan from London, Jun 4, 2013.

  1. Tan from London macrumors newbie

    Jun 8, 2005
    Hi.... yestreday in the span of 2 hours we had three power cuts for about 5 minutes each time. No idea why. Thereafter my MacPro dual core intel machine comes on and then switches after a few minutes. I have tried the command option p and R and hear the ring , then it rings again but like a struggle ring and the switches off again.

    I have managed to get the CD drive open and placed CD inside and tried switching on by pressing C but same things happens. I have an Apple extrenal CD and even that does not help.

    The mac begins to start up but switches off. Any ideas to sort this issue out please.

    Thank you

  2. Gav2k macrumors G3


    Jul 24, 2009
    Sounds like a power surge has killed your psu possibly more
  3. Tan from London thread starter macrumors newbie

    Jun 8, 2005
    Thank you for the reply re PSU

    I have a old G5 mac pro.. Can I change the psu myself? Would this have damaged the hard drive as well?

    Or could I access the hard drives by purchasing one of the hard drive external cases?


  4. The-Pro macrumors 65816

    Dec 2, 2010
    The power supplies from the PowerMac G5 and Mac Pro are totally different and cant be interchanged.

    You could put harddrives into the G5 if you want to access them or yeah buy an external enclosure.
  5. Tesselator macrumors 601


    Jan 9, 2008
    If it indeed powers up "for a few minutes" then the probability that it's the PSU which got clobbered is low. Not zero but pretty low. Usually when a PSU gets wiped you get nothing at all (no bong!). I can't make any assumptions with the current descriptions posted here but what there is seems to point to some components downstream of the PSU. The Bong means that the main board self-test is passed and that is sees RAM. After the bong IIRC, then it checks RAM, inits any cards present, and looks for a bootable device. Etc.

    Try resetting the SMC too if you haven't already. Unplug the machine, hold down the power button for 10 long seconds, then plug it back in and try again.

    Next try it with different configuration, 2 DIMMs at a time, Only one HDD (or no HDDs - just a thumbdrive), your older GPU if you still have it, and so on etc. etc. and see if it always behaves the same or differently. Write down exactly what happens and post it here. There might be someone who notices a pattern or whatever.

Share This Page