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Thread: Mac Pro status light continually blinks at startup

  1. #1
    Join Date
    May 2007
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    Default Mac Pro status light continually blinks at startup

    I have an early 2008 Mac Pro running 10.6.8. When I push in the power button
    my computer turns on and then the light above the power button continually blinks. The only sound I hear is the fans running. No beeps,no startup chime.
    I've removed all the external peripherals,extra ram,extra internal hard drives.I tried booting up from my bootable backup hard drives. I've tried all the keyboard combinations at startup but still the same problem. The light continually blinks and nothing else happens.

    Could I possibly have a hardware problem?
    Thanks in advance
    John

  2. #2
    Join Date
    Feb 2001
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    on the landline, Mr. Smith
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    Yes, sorry to say, could be.

    First, did you unplug everything including power for at least 15 seconds, and then plug in only essentials (monitor, keyboard, mouse, power) and try again? This is an SMC reset.

    If that is not it, then usually RAM related, but could be something else.

    You might try unplugging everything again, and pulling all the RAM (yes all), and then plug power back in, and push the power button once. Should beep three times, and flash. Which is the correct diagnosis for no RAM installed.

    Next, put back in 1 pair of RAM for testing, being sure to follow the specific procedure for your model (should be on the inside of the door....).

    Try this with rotating pairs of RAM to see if any behave differently....being careful to ground yourself and protect the RAM and internals from static discharge.
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  3. #3
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    Default

    Thanks Unclemac for your reply. The original ram that came with the computer was bad. Removing the bad ram and re-installing the remaining ram fixed the problem.
    John

  4. #4
    Join Date
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    Good deal. Glad it was nothing too serious.

    Though not that common, RAM does sometimes just fail/die for no detectable reason. Manufacturing defect, ESD at some point (surprisingly easy to damage this way), not seated properly.....gremlins....hard to say.

    ESD is more tricky than folks know:

    ESD Damage

    So what kind of damage can be caused by ESD (Electrostatic Discharge)? Anything from a simple system interruption, causing your computer to reboot with no further problems, to complete destruction of a chip that will make your system unusable until the chip is replaced. Also, you won't find any discoloration, burn mark or physical indication whatsoever as to which chip has been damaged.

    There are 2 types of damage that can occur:

    Immediate Failures (Direct Failures, Catastrophic Failures) - These are failures that occur immediately after the chip has been damaged and usually aren't recoverable until the chip has been replaced. Say you open your computer (or worse yet, someone else's) to install more memory. Without using an anti-static strap or a grounding mat (you've done it lots of times before and never had a problem), you take a brand new DIMM from its anti-static tube, install it, and now the computer won't even finish its boot sequence. Not a good situation, but you do know the computer worked before you installed the RAM, so you should have an idea where to start looking for the problem.

    Latent Failures (Upset Failures, Delayed Failures) - Sometimes a chip can be damaged by electrostatic discharge and the results aren't immediately noticeable. Months later the chip could finally fail completely, or you may end up with intermittent failures that occur sporadically. These are usually difficult to attribute to any specific cause, and very hard to track down.
    Thanks for the follow up!
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  5. #5
    Join Date
    Aug 2013
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    Default

    Well i know im late to the party but ya i was going to say try reseating the ram. I had the same problem with mine after i had installed a new hard drive. I was just about ready to smash it with a hammer then pulled the ram out put it back in and it loaded.

  6. #6
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    patience is a virtue!
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

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