Previous 1 2 3 4 5 6 Next 76 Replies Latest reply: Oct 9, 2015 9:00 AM by David K Oberlin Jr. Go to original post
  • MotleyPete Level 1 (0 points)
    Hi kevvo_b

    Since replacing the PSU myself (bought new on eBay for around £140) this problem has been solved.
  • Troy The Man Level 1 (0 points)

    Hey all,


    Well  have read every thrad that there is on the Web rergarding this subject, I have removed all USB devices, Removed Firewire Devices, Removed internal Hard Drives, Removed RAM, you name it, I've removed it. Sometimes the problem will go away temporarily, but then mysteriously returns.

    It is not a software issue as it occurs before the machine even starts up.

    What is interesting to me, is how the issue appears to be getting worse and now, when I do any moderatelly heavy processing, the machine shuts down.


    The only solution that I can think of, is the PSU.


    It very much seem like a dodgy Power Supply and Apple's silence on this issue would aslo support that it is faulty hardware issue. If it were not, an Apple tech would have been on to one of these threads by now, with a solution.


    Faulty PSU is likely to be the answer, so once I have changed mine, I will also confirm as has Motley Pete.


    Shame on you Apple!

  • WelshDog2 Level 1 (5 points)

    I've got an Early 2008 Mac Pro with the power off issue.  I had it at the Apple store 3 times and they could not diagnose it because the stupid thing would not power off when they had it.  Of course Applecare has expired now. Since this is a production system at a post house I can't risk it failing during a session so I guess I have to throw a power supply at it.  Naturally it has not powered itself off in over two weeks now.


    When is misbehaves this is what it does:  Operator is working and hits render in After Effects.  Boom power off. Operator is working and hits render in Media Composer.  Boom power off.  Computer is sitting idle and operator moves the mouse.  Boom power off.   Sometimes it will not power back on.  Push the button, drive and fans spin light comes on and <click> power off. It will repeat this over and over until you unplug it for a couple of hours and then it will be fine for a random amount of time.  Have run many many tests including multi day memtest runs.  It is not overheating.  Inside is clean, no dust.  This computer lives in an air conditioned server room at all times. Firmware is up to date.


    PSU is the only thing I can think to replace at this point.

  • Troy The Man Level 1 (0 points)

    If it is any consolation, you are certainly not alone with this issue. All seem to be Early 2008 Mac Pro's too. I have since contact Apple about this and surprise, surprise, "this is not a known issue that us in Apples known issue list". How strange that despite the thousands of forum posts on this issue, I am the first to bring it to Apples attention. Hooray for me. Anyway, my Mac Pro is at the menders now, at Apples advice, where I eagerly await the outcome. The tech there also suspects the PSU, but is conducting other tests to be sure. A new PSU is the cost of a cheap Windows PC, which beats the alternative which is the Logic Board, costing about the same as a good Windows PC. That being the case, my Apples days could be very short lived. I cannot afford a product that cost $4 - $5k and only lasts a couple of years. For my money an ACER i5 wins every time. I'll let you know how things go.

  • Troy The Man Level 1 (0 points)

    OK. New PSU seems to have done the trick. Apple do a kind if trade in scheme for dud parts, so got discount on new Power Supply. Fitted for free by Authorised Apple Service. $290 all up, in not ecstatic, but happyish with outcome. Mac is back and I dont have to buy a Samsung PC.

  • WelshDog2 Level 1 (5 points)

    Have ordered a new PSU from DVWarehouse.  They assure me it is a new unit - not refurb.  I will install it myself.  It's easy actually, I already removed the existing one to check cables and for dust build-up.  Pretty simple.  New unit arrives Wednesday.

  • Miguel from Salvador-BA Level 1 (0 points)

    Have you solved definitly the problem ? If yes , you had luck .

    The reality is the following: nobody knows nothing regarding a solution, that is not the exchange of logic board. Apple Computer doesn't accept that is a serial problem to give us a recall , I've reading many people saying a lot  of ******** and nobody gives the true solution, that until now is to exchange logic board . I want a solution that no envolves exchange of logic board .

    PS1: I have 8 MacPros early 2008 and have exchanged 3 logic boards and have others with the same problem , and I don't want to give more money for an error of  Apple Computer . You know that after long time , Apple accept that graphics adapter of Mac Pro early 2008 had problems and now (after july) is promoting a recall . We have to have this for logic board too . When I talk with them , they say that nobody related this problem before . It's impossible . It's a war and we have to win .

    As I have 8  Mac Pros (same model) and I have exchanged 3 logic boards , I've tested every parts of the others and I'm sure that the problem is with logic board (no power supply , no processor , no graphic adapter , no Mac OS  version , no memory , no eletrical issue , no UPS problem - Apple doesn't recomend any UPS) . I have lost much time , doing all the possible tests , with system , without system , with 17 , 20 , 24 and 26  degree Celsius , all possibilities and no solutions , except exchange logic board .

    PS2 : When one Mac Pro was under garantee , I exchanged a logic board and only two months after , I had to exchange again , because I had the same problem .

  • WelshDog2 Level 1 (5 points)

    New power supply fixed the issue.  System has had no problems, even during heavy edit session on Final Cut.  I just wish Apple had been able to do this for me since the problem started while covered by Applecare.  However, it would not fail while they had it on the bench.

  • Miguel from Salvador-BA Level 1 (0 points)

    Did you have a red led near to bluetooth connector , before exchanging the power supply ? If not, probably that is why the power supply exchange  solved your problem . Reading about using a new power supply yesterday , I decided to do a new test with a new power supply , well , I returned to the beginning , I still have a red led , and the same problem , power off suddenly alone . I can run the Apple Service Diagnostic (ASD) 1 ,2 ,3 ,n times with no problems , but suddenly , it's power off alone . Today only the 3 Mac Pros that I exchanged the logic boards , are working fine , the others ... from bad to worse .

  • David Mansfield1 Level 1 (0 points)

    I have the exact same problem, it almost seems like the system works fine one it's "warmed up"; what I want to know is how do I know if it's the PSU, since the problem is sporadic (and probably won't show up on the bench at the repair shop)? Is there any way of testing for this?



  • singhs.apps Level 1 (0 points)

    Extremely sorry for reviving an old thread but I am having the exact same problem as Motleypete.


    I am running a Mac pro 2.8 dual core [ early 2008]


    The local apple authorised service guys says it is a Logic board + CPU issue and they have to be replaced but the cost is closed to 75% of a brand new mac pro.


    Based on the posts here and elsewhere, overwhelmingly a lot of people are saying that replacing the power supply unit has solved their problem.


    @MotleyPete : Can you tell please us if you have had no similar startup issues with your mac pro since you replaced the power supply ?



  • Davey Go Level 1 (0 points)

    Hi! I just got my Mac Pro last year from Hong Kong and I rarely use mine since I also have my vaio. The problem started last night. After having the battery emptied 2 weeks ago, I switched the power on while it's connected to a power supply. The moment the screen lighted up, it gives a message that the time and date were erroneously been set and that may result to some systemic problems. So I manually reset the time and date. I then charged my ipod and inserted my WD external drive and watched few videos. The Mac freezes a bit at the beginning but it eventually turns smooth later on. I watched videos for 30 minutes and then I turned it off to fully charge the machine. Then I switched  it on again this afternoon, the screen is simply frozen with itunes on the screen. I tried to quit the application to no avail. So I did the force shut down by long pressing the power button until it switches off. It first turns off, but when I turned it on again, it only sprouted with an apple logo and a loading bar, then after 20-30 seconds it turns off. Tried resetting the PRAM, it still not functioning. My place is far from any apple centers, so I need a good suggestion. If it's the PSU, is it very possible if the got my mac a year ago?


    Thanks A lot!

  • The hatter Level 9 (60,930 points)

    Then with this: After having the battery emptied 2 weeks ago, This is not a Mac Pro but a laptop.


    MacBook Pro


    So I did the force shut down by long pressing the power button until it switches off. It first turns off, but when I turned it on again, it only sprouted with an apple logo and a loading bar, then after 20-30 seconds it turns off.


    A Mac Pro needs a UPS to provide good clean even power (and take some of the work off PSU too).


    A hard forced power off will corrupt the directory or more only adding to the problem(s) and should have a restore system image / clone of your system / make use of Recovrey partition / followed by Safe Boot.


    If you have a 65 lb tower workstation, did not sound like it to me.

  • Davey Go Level 1 (0 points)

    Read your reply couple of times yet I have some problems with the technical words. I'm a little dumb with computers, could you please elaborate your suggestion?


    Does it mean that the Power Supply Unit is still OK?


    I would really appreciate it you responding. Thanks!

  • Dan Suthers Level 1 (0 points)



    What is the difference between "614-0409" and "661-4677"? Are they same and interchangeable


    Wondering whether this has been answered here or elsewhere. I ordered a 661-4677 to replace what's in my Mac Pro (Early 2008), and was shipped a 614-0409. Should I return this as "wrong item" or are they functionally equivalent?


    thanks so much -- Dan