Mac Pro 4,1 No boot/chime

Discussion in 'Mac Pro' started by jquinn88, Jul 23, 2016.

  1. jquinn88 macrumors newbie

    Jul 23, 2016
    I have two Mac Pro 4,1's that I got free from work. One is my main machine and works great (SSD upgrades, Video cards, USB 3.0). The other does not boot or chime. ame specs. Something on the CPU tray is faulty. I've done the following:

    Swap CPU tray from Working computer (A) to B and it booted up/chimed. I even swapped out the ram from B to A to make sure that the Ram was not the culprit. B's tray mounted in A's computer does not boot/chime

    I've looked around and it seems that the CPU may have come unseated or an issue with the thermal paste? How should I go about testing the bad tray to diagnose?
  2. leon771, Jul 23, 2016
    Last edited: Jul 24, 2016

    leon771 macrumors regular

    Sep 17, 2011
    Download technicians manual for 2009 Mac Pro and follow troubleshooting.
    Unless someone fiddled with heatsinks there's no way a cpu can just unseat itself.

    People always talk about northbridge heatsink coming loose. I would think this would cause machine to shut off when hot, not prevent a boot.

    Sounds like something terminal wrong with logicboard.
  3. ActionableMango macrumors G3


    Sep 21, 2010
    I agree with Leon. The Service Manual has good troubleshooting procedures in it.

    The chime occurs after a successful POST, so something is not passing that test.

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