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User profile for user: Community User
Community User Author

2012 Mac Pro whitescreen when turned on

I recent received a 2012 Mac Pro system. It was filthy, but working. Last night I disassembled the system and used canned compressed air to blow out the crud from inside the system. I reassembled the system and it was working fine.


This morning I powered up the system and I just get a white screen and a chime. Sometimes the tail end of the chime will repeat at about one second intervals.


I've tried holding SHIFT to get to safe mode, holding the power button for 10+ seconds, pressing the PRAM reset button on the mainboard, replacing the PRAM battery, reseating the video card and reseating the CPU card, but no change.


I notice that there is a DIAG LED button, but not sure what to expect when pressed.


Specs are dual Xeon 6 core processors, 48 GB of memory, 512 GB SSD drive, nVidia GTX 680 video card.


Any idea what I can do from here?

Mac Pro

Posted on Mar 1, 2021 3:11 AM

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User profile for user: Community User
Community User Author

Posted on Mar 1, 2021 6:14 AM

So, the answer is...


My KVM. Unplug the KVM from the USB port and my Mac boots fine. It doesn't matter what's connected to the KVM, nor what computer the KVM is set for. The Mac just won't boot if it's connected.

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User profile for user: Community User
Community User Author

Mar 1, 2021 6:14 AM in response to Community User

So, the answer is...


My KVM. Unplug the KVM from the USB port and my Mac boots fine. It doesn't matter what's connected to the KVM, nor what computer the KVM is set for. The Mac just won't boot if it's connected.

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User profile for user: Community User
Community User Author

Mar 1, 2021 4:19 AM in response to Community User

One last thing to note...


If I hold the power button when I turn the computer on, I get a rapidly flashing power light for a couple seconds, then a long beep, then the computer doesn't do anything else but whitescreen.

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User profile for user: Community User
Community User Author

Mar 1, 2021 3:33 AM in response to Community User

FYI... For the diagnostic LEDS, I have the following...

  • PSU PWROK is green
  • 5v STBY is yellow
  • SYS PG- is green
  • GPU OK is green

Anything else is not lit

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2012 Mac Pro whitescreen when turned on

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