Mac Pro power supply testing

Discussion in 'Mac Pro' started by dintymoore, Jan 18, 2011.

  1. dintymoore, Jan 18, 2011
    Last edited: Jan 18, 2011

    dintymoore macrumors newbie

    dintymoore

    Joined:
    Jun 27, 2008
    #1
    A friend of mine has a music studio and his Mac Pro (dual 2.66 GHz Intel) won't start in the morning. Completely dead. If you take the cover off and use a hair dryer for 30 seconds it will start, and will start normally once warm. We've reinstalled Leopard a few times as well as swapped hard drives, done Disk Utility repairs many times and the hardware test says all is good. I'm thinking power supply or logic board.

    Is there a pin out voltage test you can perform on the power supply?

    Is it possible to test the power supply that way?

    Also, has anyone tried using electronic freeze spray to try and diagnose intermittent problems like this?

    Thanx
     
  2. cutterman macrumors regular

    Joined:
    Apr 27, 2010
    #2
    If that is an older model you should be able to test the +5 and +12 rails on the 4 pin molex connector that should be unattached in the second optical drive bay.
     
  3. dintymoore thread starter macrumors newbie

    dintymoore

    Joined:
    Jun 27, 2008
    #3
    Thanks cutterman.

    I know the Molex connector you are talking about so I'm guessing it's an older model. I will check those voltages. It will be a few days before I'll be in his studio to do that.

    Could there be juice at that connector and the power supply still be bad, or is that unlikely?
     
  4. cutterman macrumors regular

    Joined:
    Apr 27, 2010
    #4
    Yes. First off you can't check the 3.3V rail from that connector. Second bad PSU's can cause reboots and other random problems when the voltages drop under load, like at startup. So a normal reading when the machine is on and stable wouldn't rule out a bad PSU. Hook up the meter while the machine is off and see what happens at power on.

    BTW, what do you have to heat up with the hair dryer to get it to work?
     
  5. dintymoore thread starter macrumors newbie

    dintymoore

    Joined:
    Jun 27, 2008
    #5
    I took the cover off and held a hair dryer about 8" away from the open area around the empty PCI-E slots, under the power supply. I didn't aim it at anything in particular and I didn't do it very long, more of a gentle warming up. It powered up right after and the owner said that's worked pretty much every time. I had tried the power switch for about 20 min to no avail while we were making coffee before that.
     
  6. bmorris macrumors 6502

    bmorris

    Joined:
    Nov 8, 2007
    Location:
    ATL
    #6
    I have a 2010 quad core and I have had a few instances of the Mac Pro just cutting off. Not shutting down, but like the power was pulled. And I have to wait at least 30 seconds to turn back on. A red light blinks from inside. It's connected to an APC BE350R battery back up. But I have had same issue when running to wall. All plugs are secure and not loose.
     
  7. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #7
    From what you describe, the PSU is shot and needs replaced. If you still have Apple Care, take it in before it expires. I presume you don't however, so be prepared for a bit of sticker shock, as the last time I saw the cost of a replacement unit, was ~$300USD.

    BTW, bad electrolytic capacitors can cause this (likely suspect).

    The red LED's indicate a hardware fault, so running the Apple Hardware Diagnostics program may help (assuming you have it or can get a copy). It could be something simple, like need to swap memory around (i.e. needs to be reseated, or actually have a bad stick).

    I presume you do still have Apple Care, so schedule an appointment if you can't sort it via the diagnostic program/don't have access to it (the repair personnel do have this particular piece of software if you don't have it, or can get access to a copy - it would need to be recent enough it covers your system, so make sure if it's an older/borrowed copy).
     
  8. bmorris, Apr 7, 2011
    Last edited: Apr 7, 2011

    bmorris macrumors 6502

    bmorris

    Joined:
    Nov 8, 2007
    Location:
    ATL
    #8
    I ran the Apple Hardware test (version 3A207) and the normal test was okay. I ran an extended test and got an error. 4MEM

    4MEM/62/40000000: 0x79ac7698

    Pass Number:2,
    Total Time Testing: 34m 21s

    I Googled the error and similar codes meant DOA memory.
    I contacted Newegg about the G.skill sticks and they said to contact G.skill for replacement sticks.
    Waiting to hear back now.
     
  9. Joshuarocks macrumors 6502

    Joshuarocks

    Joined:
    Mar 12, 2011
    Location:
    Somewhere in Cyberspace
    #9
    Just use Apple Service Diagnostic and you would see the exact same error, but in SIMPLE ENGLISH.. those cryptic codes just confuse anyone.. if you don't have ASD 3S132, Let me know.
     
  10. bmorris macrumors 6502

    bmorris

    Joined:
    Nov 8, 2007
    Location:
    ATL
    #10
    Where would I get this? I don't think I do.

    G.skill said
    "Unfortunately it is because the Mac Pro needs fully buffered, ECC memory.That system is like a server or workstation, so special memory is required. Unfortunately G.Skill only produces end user PC memory."

    I asked to still send new memory and they said okay.
     
  11. Joshuarocks, Apr 7, 2011
    Last edited: Apr 7, 2011

    Joshuarocks macrumors 6502

    Joshuarocks

    Joined:
    Mar 12, 2011
    Location:
    Somewhere in Cyberspace
    #11
    Yours truly :)

    Let me know if you want it. Its still good to have in case you ever have other problems later on with your Mac Pro, as it takes the errors and gives you them in simple english sentences and words, and not cryptic mumbo-jumbo. Consider it a nice tool to have..
     
  12. bmorris macrumors 6502

    bmorris

    Joined:
    Nov 8, 2007
    Location:
    ATL
    #12
    Where would I normally get it?
    I'll take it though, how can you send it?
     
  13. Joshuarocks macrumors 6502

    Joshuarocks

    Joined:
    Mar 12, 2011
    Location:
    Somewhere in Cyberspace
    #13
    You can't get it anywhere accept from those who have it.. Its the most comprehensive of testing for any mac machine known to man.. and only service providers have it.. however, I have all of them for every machine.. Let me know if you need the one for your Mac Pro...

    I have helped 1000's of people in your situation.. I am also on Apple forums and help lots of people diagnose their machines and help them anyway I can.
     
  14. beto2k7 macrumors 6502

    Joined:
    Jan 6, 2010
    Location:
    ::1
    #14
    I'd like to have it for a 09 Mac Pro if you can please. I currently dont have any problem with my mac but like u said, it's good to have AHD just in case.
     
  15. bmorris macrumors 6502

    bmorris

    Joined:
    Nov 8, 2007
    Location:
    ATL
    #15
    I have a 2010 Mac pro, early 2009 13" MacBook Pro, unibody 13" MacBook, and late 2009 Mac Mini.
    Would I need one for each model? I would def want one for Mac Pro. The others would be nice.
     
  16. H2SO4 macrumors 68040

    Joined:
    Nov 4, 2008
    #16
    You might be just the man I need......

    Joshua Rocks, can I ask you to take a look here...........?
     

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