2009 Mac Pro - 2.66Q: DSI510 CPU Tray LED Lit (PROCHOT or Proc Missing), "powers on" but no peripheral or display.

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Level 1

4 points

2009 Mac Pro - 2.66Q: DSI510 CPU Tray LED Lit (PROCHOT or Proc Missing), "powers on" but no peripheral or display.

I'm banging my head on this problem over here and I'd love another opinion. I'm trying to troubleshoot a Mac Pro remotely via messages, and I'm getting very simple responses and many questions glossed over because English is their second language. I'd really like to help them. I know the computer was fine. I don't want to eat the $70 I spent to ship it, or the $70 return shipping and the having to now deal with the broken computer.

So, I've got this eBay customer who I sold an 09 Mac Pro ( http://www.ebay.com/itm/142212486470 ) that I knew was in fine working condition when it left my door well packed. According to him, he added a 'Radeon GPU', 16 GB RAM, and HDD and it worked for three days.

He's got the DSI510 CPU Tray LED lit when he turns it on; the Apple Technician Guide says this is overtemp PROCHOT or Processor missing state.

I tried to get him to reseat the CPU tray, reset SMC and PRAM, and hit the DIAG_LED button and report all indications.

He says :

"

!- Please look at the photo of the CPU Tray I have attached, and confirm that the location of the red LED in the photo matches where yours is showing up

yes this is

2_ I have full the Memory slots 4 memory for 4 gb 16 gb total

3 when the computer is up No power in fans no power in USB ports .

4- you'll see an array of LED's with a DIAG_LED button……only when I Hold the button , only 5 volt estan by in orange color not another let array is on

5.-Reseat the CPU tray, ….. this is ok

6.-Reset the SMC and PRAM: Cant usb keyboard not work

Thank,,"

"

Okay, customer says when the computer powers up he's got no fans and no USB power. He says he's got an orange 5V LED when he hits the DIAG_LED button, and that he cant reset SMC and RAM because he doesnt have USB power for the keyboard (well.. PRAM for that matter since SMC is reset when you leave it unplugged).

I have another Mac Pro here that I can troubleshoot with, but I'm out of ideas if I can't reproduce the error in front of me.

Advice would be invaluable! Thank you.

Mac Pro, macOS Sierra (10.12.2)

Posted on Jan 2, 2017 11:19 PM

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Answer 1

Best reply

Grant Bennet-Alder

Level 10

127,135 points

Jan 4, 2017 3:43 PM in response to relliMmoT

the conventional way to debug these problems is to strip the system down completely. Remove ALL drives, ALL PCIe cards (yes, pull the graphics card as well), and if desperate ALL RAM. Then attempt to power on. You should get the Power-on light blinking in groups of three, that says, "processor is alive, but not enough RAM to start up".

Next put in ONE RAM (in this Mac, that is all that is needed, and it is said it can start up in a s little as 96K). you should get the chime and the solid power light, as well as the fans. Or you get a red light next to the RAM because that RAM is no good (for this particular Mac).

Then add as many as three RAMs total. Four RAMs is much more difficult than three, because slots 3 and 4 are shared.

then one thing at a time in a step-by-step process. The addition of a bum graphics card or a graphics card without connecting its aux power cables can kill everything and send you back to the beginning.

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Answer 2

relliMmoT Author

Level 1

4 points

Jan 4, 2017 12:39 PM in response to relliMmoT

Dang. I could really use some help on this one.

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