Mac pro 5.1 flashing light thing.

Discussion in 'Mac Pro' started by Andy kimbo, Mar 24, 2018.

  1. Andy kimbo macrumors newbie

    Andy kimbo

    Joined:
    Mar 24, 2018
    #1
    Hi.
    First post so don't beat me up too much.
    My mid 2010 5.1, 4 core running 10.11 El Capitan has developed a constantly flashing power light.
    It won't boot.
    Fires up with fans & drives kicking in, but after a few seconds the power light flashes & that's your lot.
    I'm sure this has been covered many times in the past, but I've never seen a resolution on any other forum.
    Thinking it was a ram issue,
    I swapped the ram sticks around until it seemed that ram slot No2 was at fault.
    I then stuck my 3, 8 gig sticks of Kingston ram in slots 1,3, & 4 & all was fine again.
    Fired it up a week later & the flashing power light is back, but this time no amount of ram configuration works using 1,2, or all 3 ram sticks.
    I've unplugged stuff (including the graphics card)& that type of thing but to no avail.
    Is it likely all 3 sticks of ram have failed?, or is there something more sinister going on?
     
  2. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
  3. Andy kimbo thread starter macrumors newbie

    Andy kimbo

    Joined:
    Mar 24, 2018
    #3
    kingston kta-mp1066qr/8g.
    You raise an interesting question.
    They were sold as ECC ram. & although they have stopped making them, the info is still there on various
    websites as being ECC ram. Except on Kingstons own website where it states ECC - No.
    But it's been in there for 4 years without a hitch.
     
  4. tripmusic macrumors 6502

    tripmusic

    Joined:
    Oct 26, 2012
    Location:
    MA
    #4
    System Information will tell you whether they're ECC or not. Maybe try an SMC reset? Clean the RAM and slots with contact cleaner or alcohol?
     
  5. Andy kimbo thread starter macrumors newbie

    Andy kimbo

    Joined:
    Mar 24, 2018
    #5
    Done SMC, & PRAM reset. All contacts clean as a whistle.
    Although I can't remember 4 years ago (much) But I'm sure I would have checked system info to confirm there was
    the correct amount of ram, & whether it was ECC or not. I've always done that..
     
  6. ActionableMango macrumors G3

    ActionableMango

    Joined:
    Sep 21, 2010
    #6
    You need to look at the diagnostic LEDs inside the case. There are many. They will provide a more clear picture of what is going on. Also, do a google search for the service manual. The service manual will tell you want the diagnotic LEDs mean.

    I doubt it is all 3 previously working RAM sticks failing at the same time. That would be absurdly unlucky. I think you have an intermittent problem and the initial fix of moving the RAM sticks was just a red herring.
     
  7. Andy kimbo thread starter macrumors newbie

    Andy kimbo

    Joined:
    Mar 24, 2018
    #7
    Update...
    No diagnostic lights on with any configuration of any of the Kingstone sticks. Will not boot..
    Now I've found my old Apple ram 3 x 2gig. (pc3 10600e)
    Placed them in, & it booted. After another PRAM reset everything was fine for half an hour.
    Mac panicked & shut down.
    This is what I'm getting now:-
    The mac boots. But sometimes shuts down & restarts during boot.
    Sometimes diagnostic lights are on ram slot 2, or 3, or both.
    Most times any one of the 3 sticks, or all of them are reading errors.
    Without any real knowledge of how a mac really works,
    I'd say it's still telling me it doesn't like the ram because it's in some way bad..
    But that would then suggest I've now got 6 sticks of ram that are rubbish.
    The Apple ram has been in the loft for over 4 years though. (I thought I'd never use it again).
     
  8. ActionableMango macrumors G3

    ActionableMango

    Joined:
    Sep 21, 2010
    #8
    There are more than just the RAM LEDs. There are diagnostic lights that should always be on if the Mac is on. Did you look at the service manual yet? Do a Google search for the 2010 Mac Pro service manual and go to the diagnostic LED section.

    There's no way 2 sets of 3 sticks have all coincidentally gone bad at the same time.
     
  9. Andy kimbo thread starter macrumors newbie

    Andy kimbo

    Joined:
    Mar 24, 2018
    #9
    As far as i've seen so far, none of the diagnostic led's have come on in any colour.
    When I disconnect or reconnect the power supply, the two led's at the top flash which I understand to be normal.
    The only led's lighting up when the mac is on is sometimes ram slot 2, or3, or both.
    I don't know which of the other lights is supposed to be on all the time.
    I've downloaded the service manual but haven't come across much in the way of some kind of answer.
    (That I understand at least)...
     
  10. ActionableMango macrumors G3

    ActionableMango

    Joined:
    Sep 21, 2010
    #10
    I'd do the procedure that starts on page 33. The LEDs are mentioned in that procedure.
     

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