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Q: '08 Mac Pro flashing status light no tones

My Mac Pro has a steady..flashing status light..Will not boot and has no tones...Began after a power outage but it has survived many outages before and always restarts automaticlly ...I have tried pram..unpluging etc...This is a steady flashing about a second apart..Doesn't seem to be any of the trouble shooting codes.  I switched out the power supply with another one bought from a reputable seller but get the same thing..I hope someone has an answer for me...Thanks...

Mac Pro, Mac OS X (10.7.2), I've tried all the suggestions I co

Posted on Oct 20, 2015 7:19 PM

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Q: '08 Mac Pro flashing status light no tones

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  • by Grant Bennet-Alder,Helpful

    Grant Bennet-Alder Grant Bennet-Alder Oct 20, 2015 7:44 PM in response to windsail
    Level 9 (60,707 points)
    Desktops
    Oct 20, 2015 7:44 PM in response to windsail

    The most common cause of blinking power light is "not enough working RAM to start up."

     

    It may have worked yesterday, but the DIMMs in these Macs get hot, and they fail at a fairly high rate.

     

    In some cases, the red lights may stay on next to the DIMMs that are not working. But that may be when the failure occurs later in the process,

     

    The good news is that that blinking is done under software control, so your Mac is probably fine otherwise.

  • by windsail,

    windsail windsail Oct 20, 2015 7:57 PM in response to Grant Bennet-Alder
    Level 1 (0 points)
    Oct 20, 2015 7:57 PM in response to Grant Bennet-Alder

    Thanks Grant....Do you know if I could test this in any way?...Pull the dimms out?...In the original manual  says:

     

    "One short flash followed by a longer off period......No valid memory

     

    "Three short flashes followed by a longer off period....Failed memory

     

    But I am having a constant...steady flash and nothing more..doesn't stop or alter sequence at all...no tones..

     

    I appreciate your help very much...I did add some memory a few years ago ...maybe it wasn't the best..wasn't Apple but was 'sposed to be ok.

     

    Thanks again...Shawn McCafferty

  • by Grant Bennet-Alder,

    Grant Bennet-Alder Grant Bennet-Alder Oct 20, 2015 8:21 PM in response to windsail
    Level 9 (60,707 points)
    Desktops
    Oct 20, 2015 8:21 PM in response to windsail

    Pull the side door and check for LEDs next to the RAM positions. It is not interlocked, but components can be HOT.

     

    The RAMs in these machines are in pairs, so the failure of one of a pair means neither can be used.

  • by windsail,

    windsail windsail Oct 20, 2015 8:41 PM in response to Grant Bennet-Alder
    Level 1 (0 points)
    Oct 20, 2015 8:41 PM in response to Grant Bennet-Alder

    Ok...I opened up and when I power up both upper and lower red lights come on but go off immediately..does that tell you anything?

     

    I have three sets of ram installed...One two gig set..original...And two four gig sets....

     

    Thanks for stickin' with me Grant...Shawn

  • by Grant Bennet-Alder,Helpful

    Grant Bennet-Alder Grant Bennet-Alder Oct 20, 2015 8:53 PM in response to windsail
    Level 9 (60,707 points)
    Desktops
    Oct 20, 2015 8:53 PM in response to windsail

    the Apple article on the subject suggests you re-seat the modules, and if that don't help, get some new ones:


    Intel-based Mac Power On Self Test RAM error codes - Apple Support

     

    .

  • by windsail,Solvedanswer

    windsail windsail Oct 20, 2015 8:58 PM in response to Grant Bennet-Alder
    Level 1 (0 points)
    Oct 20, 2015 8:58 PM in response to Grant Bennet-Alder

    Maximum thanks Grant...Will do...I did call Apple and they "knew nothing"...but at least they didn't charge me for the call..

     

    I'm almost sure that's the problem...old system..cheap memory..dusty environment....I spent two hundred on a power supply

    but now I have a back up....And thanks to you I feel sure it will solve my problem...

     

    I've resurected my old G4 that I'm on now....boy...how slow..

     

    Thanks again Grant and a good evening to you.....Shawn McCafferty....windsail...