Mac Pro Will Not Power Up

  1. #1
    Hi all, I am new to this forum,. Thank you an advance for taking the time to help out.

    Apple Mac Pro 2009 3.46GHz Xeon 6-Core Westmere

    My studio computer arrived DEAD,... I am building my new Christian music recording studio in the Philippines,.. so shipping the machine back to the USA is not really an option.. shipping will cost about the same as a new machine.

    I will try to describe the symptoms.

    - It will only start 1 or 2 times a day and will shut off on its own after about 3 minutes.

    - When it starts it boots perfect and performs fast and smooth. I am able to open and navigate through the software. Then shuts off after about 3 minutes or less.
    - Even with no mouse, keyboard or monitor plugged in it shut off after 3 min.
    - When plugging in the machine,. and on start up 2 Red LEDs flash on the top left motherboard. also 1 Red LED flash on the CPU board.
    - A couple times it started up when I plugged in the power cord (I did not push the power button)

    Every day for the last 4 days it starts fewer times,. today and Yesterday it would only start one time after sitting overnight.

    Today it tried to start then clicked off instantly.

    I re-seated the HDDs, Memory, Video card, CPU, PSU connector, and checked all the other connectors.

    I tried each memory stick in slot 1 (only 1 stick installed at a time)

    I tried with 2 separate Hard drives.

    Maybe a bad PSU ?

    Thanks in advance,

    Steve Perkins

  2. Mac Pro Will Not Power Up

    My guess is that you have a flaky power supply. Older Mac Pros are famous for eating power supplies.
  3. Steve.P thread starter macrumors newbie

    Hi Thanks for the fast reply !

    I think that might be true... Everyday it will start less and less times... now its only maybe one time a day and then a quick power off.

    Fans spin on start up.

  4. Mac Pro Will Not Power Up

    That's typical. As soon as a load gets on the supply, it quits. Check eBay for a replacement but make sure you deal with someone who will offer a refund if it turns out it's something else.
  5. Mac Pro Will Not Power Up

    Apart from PSU, may be you can check the Northbridge temperature. If the plastic rivet is broken, the NB will getting hotter and hotter, and once hit the temperature limit, it will shut down the Mac.
  6. Steve.P thread starter macrumors newbie

    So,. Update.. today I checked the CPU Heatsink screws,. they were good,. loosened, tested... Re tightened. = No Change

    Then I removed the Processor, the Heatsink and tested with Nothing installed but the PSU. = Still No Start up. And then I did the following test...

    - With only the Processor tray installed According to the 'Minimum Configuration Testing'

    When pressing the DIAG button I should get The following LEDs.
    Amber 5v STBY , PSU PWROK (green) , EFI DONE (green) , GPU OK (green) .

    - The Only LEDs I get are, 0VTMP CPUA and OVTMP CPUB (red) these Flash when I plug in the power cord and un plug the cord.

    When I press DIAG the 5v STBY (amber) LED lights.

    I did test the PSU on the bench, all i can confirm is its putting out 12v. I cant load test it properly.

    Any thoughts ?

    I am guessing its either the Motherboard or PSU

    I kinda need to be as sure as I can be because I have to ship it to the Philippines and it is very expensive and takes a long time.


  7. Mac Pro Will Not Power Up

    Check temperature of Northbridge. Look at Temperature Gauge at the App Store. If you want manual control of fans buy TGPro outside of Mac Store. With that I was able to run fan at max speed and use figure out machine was usable and stable for few minutes.
  8. Mac Pro Will Not Power Up

    Why not swap out that PSU? You can't properly load the PSU on your bench unless you have the right equipment. I've run into power supplies that will put out the correct voltage until loaded down - and that's when components start to fail.

    If that machine has a bad logic board, it may not be worthwhile to repair it.

  9. #9
    8 year old PSU and system is having startup issues? I would swap it.
  10. Steve.P thread starter macrumors newbie

  11. Mac Pro Will Not Power Up

    I don't where you are in the Philippines but I remember my days in the military (Clark AB on Luzon), that the power there was atrocious with brown outs occuring often. I highly recommend whatever you wind up doing that you buy a good UPS and keep your equipment on it at all times. I can understand your reluctance to order a PSU from the states and maybe it won't solve the problem, however, you really don't have much choice.
  12. Mac Pro Will Not Power Up

    Remove the CPU Tray.

    I dont remember if you need to remove cpu heatsink to remove the CPU daughter card from the tray/carrier.

    If you can, then look on the underside and check if the plastic clip for the Northbridge heatsink is intact.

  13. Steve.P thread starter macrumors newbie

    Hi, Yes I have a UPS and AVR (auto voltage regulator) It is still the same as it was when you were here .. lol ,.. we loose power almost everyday Mac Pro Will Not Power Up

    I am happy to get a PSU,. I just want to be as sure as I can be that's the problem and not the Mother board/Backplane somehow limiting the PSU,. telling it to shut down.


    --- Post Merged, Dec 29, 2017 ---
    Hi, yes I did check the northbridge,. it is secure to the PCB. On this machine I have to remove the Heatsink to see the Northbridge.
    Thank you,
  14. #14
    What do you mean it arrived dead? Did you just purchase it? If so have you spoken to the seller about the problem?
  15. Steve.P thread starter macrumors newbie

    Hi,. I am in the Philippines,. just bought it,. but shipping takes 3 months by boat,, the seller offered to have me ship the machine back to have it replaced/repaired But shipping / customs will cost as much as a new Mac... if I ship fedx/USPS etc.. so I wanted to try and fix the bad part,, shipping a small part is much easier than the whole computer.
  16. #16
    I can agree with that. IMO the seller should cover shipping since it was DOA. In fact he should just send you another one or, at a minimum, the suspect part(s).
  17. Steve.P thread starter macrumors newbie

    I got another PSU and Motherboard today. Mac Pro Will Not Power Up

    Now the computer and PSU will start,. but no startup sound, not booting at all.

    - With the new Motherboard it will not boot at all... Is any 2010 motherboard compatible with the 3.46GHz Xeon 6-Core processor ? or is there some kind of upgrade ?? firmware ??

    - I did notice the original PSU Fan is not spinning... ( the big fan mounted in the chassis is not spinning its the one that plugs into the backplane board)

    - I think my original PSU is OK. The first thing I tried was to put the New PSU in the original case and it started up,. and then shut down 30 seconds later. (PSU fan was not spinning) All other fans were spinning slow.

    Any advice ?


  18. #18
    Have you tried doing a bare configuration with the new motherboard and PSU? If both of those were known working, something else could have failed short-circuiting the motherboard or PSU.
  19. Steve.P thread starter macrumors newbie

    Hi Yes I did the minimum configuration test with the new backplane and PSU. And all is as it should be until I add the CPU. Then it fails the test. No start up chime. No boot.

    Maybe they shipped me a motherboard that is not compatible with my CPU. (or my CPU is also dead)

    Would different firmware on the motherboard and CPU cause the machine not to boot ?