Upgraded Mac Pro CPU A Heatsink not working?

Discussion in 'Mac Pro' started by Emen Mali, Aug 9, 2014.

  1. Emen Mali macrumors newbie

    Jul 22, 2014
    Chicago, Illinois
    My upgrade went pretty well and I'm hoping someone can help me with 1 small issue. After upgrading my 2009 to a 5,1 (12x3.33), CPUA heatsink does not show up in iSTAT or Temperature Monitor, however both CPUs are fine. Of course the fans are on high and I've managed to bring them down using Macs Fan Control. But my biggest concern is that I might have placed the heatsink connector in wrong! Is it possible this could be causing the heatsink to not register? Or do I need a new heatsink?
    I've already taken it out again and there were no crushed pins. What else could cause the heat sensor to now display and have the fans rev up?
    Also, how long does one have to leave the Apple Hardware Test running? 1 minute into testing and the program freezes!
  2. hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA
    Look in the heatsink vent openings and verify that the CPU fan connector is actually fully inserted. It is very easy for the fan connector to pop out of the holding clips while you are putting the heatsink on, and that will cause the other fans to be run at maximum as a safety precaution.

    You can probably use a thin tool to push down the connector and fully seat it without having to remove the heatsink and start all over again.
  3. bxs macrumors 6502a

    Oct 20, 2007
    Seattle, WA
    Did you in any way disturb the wiring protection when removing the connector from its plastic retaining clip.... or maybe the wiring is pinched as you replaced and secured the heat sink down turning the 4 bolts.
  4. MacVidCards Suspended

    Nov 17, 2008
    Hollywood, CA
    Hopefully a pinched wire or loose connection.

    There was someone at Netkas boards in last year or so wringing his hands in fear as he had similar symptoms on several 4,1s he was upgrading.

    I don't recall the outcome
  5. Emen Mali thread starter macrumors newbie

    Jul 22, 2014
    Chicago, Illinois
    ok, i'll have to look again. Am I taking a chance leave the fan on and not seeing the heatsink being registereD? Any likely damage to the CPU?
  6. CASLondon macrumors 6502a

    Apr 18, 2011
    I would not leave it in a state where the fans run hard all the time. Monitor the CPU A temp and keep it in range, or you could damage it.

    The above mentioned pinched/loose connection is possible, but also be sure that you seated the connector facing the right way. I do remember reading that seating the heatsink connection backwards would cause a problem (one sign being that the fans would run full blast all the time).

    One side has a central tab (that you might have trimmed), the other two wider tabs (also that you might have trimmed). It should be that the heatsink cable already was shaped a bit and its not that easy to turn backwards, but check it.

    Or maybe the heatsink is torqued down ON the cable instead of tucked inside. All things to look at.
  7. derb ryan macrumors member

    Apr 1, 2014
    Hi, did you ever solve this issue? I connected the heatsink wrong and have the very same problem. Replacing the heatsink didn't help

Share This Page