MP 1,1-5,1 Mac Pro 5,1 (2010) won't boot. No fan, no chime, red DSI510 leds

[Tazintosh]

Hi folks,

A friend of mine owns 3 Mac Pro 5,1.
I'm a bit used to these machines as I've fully cleaned/upgraded its first two (non speaking mines.)
The third one had a dead PSU, so he bough a new one and gave it to me for a fresh start and upgrade.
It's a basic 5,1 Dual 2.4 GHz, with Radeon 5770.

I've mounted the new PSU and pressed the power button:

• PSU triggers (click).
• Two red leds are lit up on the CPU tray, next to each heatsink (DSI510 leds).
• GPU fan runs.
• No other fan is running except the two small fans inside the heatsinks that are kicking up full speed after a few seconds.
• No chime, no spinning drive, no boot.
• No Caps-Lock

I've precisely followed the Apple Service Manuel procedure and started a "Minimum Configuration Testing".
Since CPU must be removed during this procedure, I also took advantage of this moment to fully clean and redo the thermal paste of the NorthBridge (and later both CPU).

I can successfully reach step 4 to 6 of the "Minimum Configuration Testing":

4. Press the DIAG button, and verify 5V STBY LED (amber) illuminates.

5. Disconnect AC power cord. Reinstall processor cage with fans and processor board. Do not reinstall processor(s), heatsinks, or memory.

6. Connect AC power cord. Press the DIAG button to verify the 5V STBY LED illuminates. This is a verify step, as you’ve added modules since previous step.

Then I did step 7 but never got "Front and rear processor cage fans (and PCIe fan, if installed) should spin slowly"

7. Momentarily jump the SYS_PWR solder pads to turn ON the Mac Pro.
Expected behavior:
• Front and rear processor cage fans (and PCIe fan, if installed) should spin slowly
• One red-colored error LED illuminates on the processor board (next to the memory slots).

If I press and hold the DIAG button as recommended on step 8

8. Press and hold the DIAG button.
Expected behavior:
• PSU PWROK (green), 5V STBY (amber), EFI DONE (green), GPU OK (green) LEDs illuminated
• No startup tone
• Front and rear processor cage fans (and PCIe fan, if installed) should spin slowly

Here are my lit leds compared to the expected behavior:

Expected behavior	ME
PSU PWROK (green)	PSU PWROK (OFF)
5V STBY (amber)	5V STBY (amber)
EFI DONE (green)	EFI DONE (green)
GPU OK (green)	GPU OK (green)

This PSU PWROK off is weird to me has I would consider the new PSU as valid since it worked when placed in another Mac Pro.
The CPU tray also worked when placed in another Mac Pro.
I've done the RTC reset, the SMC reset, but no PRAM has the computer doesn't reach this far.

Other leds behavior to be aware about:

• When the power cord is plugged, OVTMP CPUA and OVTMP CPUB briefly flash red, as expected.
• But when the power cord is removed, as far as my eyes can still see, the leds are not flashing while they apparently should too.
• If I replug the power cord within a couple of minutes, the leds will not flash again. I've to wait more time for them to flash.

Thanks a lot in advance for any thought.
Regards.

 

[tsialex]

Hi folks,

A friend of mine owns 3 Mac Pro 5,1.
I'm a bit used to these machines as I've fully cleaned/upgraded its first two (non speaking mines.)
The third one had a dead PSU, so he bough a new one and gave it to me for a fresh start and upgrade.
It's a basic 5,1 Dual 2.4 GHz, with Radeon 5770.

I've mounted the new PSU and pressed the power button:

• PSU triggers (click).
• Two red leds are lit up on the CPU tray, next to each heatsink (DSI510 leds).
• GPU fan runs.
• No other fan is running except the two small fans inside the heatsinks that are kicking up full speed after a few seconds.
• No chime, no spinning drive, no boot.
• No Caps-Lock

I've precisely followed the Apple Service Manuel procedure and started a "Minimum Configuration Testing".

This is completely useless if you don't have access to Apple's LITTLEFRANK interface. Complete waste of time.

The Apple Technician Guides for Mac Pro up to 2019 Mac Pro are for Apple and AASPs technicians that have Apple tools for diagnostics, not an end user or a third party technician that doesn't have access to Apple tools.

Since CPU must be removed during this procedure, I also took advantage of this moment to fully clean and redo the thermal paste of the NorthBridge (and later both CPU).

I can successfully reach step 4 to 6 of the "Minimum Configuration Testing":




Then I did step 7 but never got "Front and rear processor cage fans (and PCIe fan, if installed) should spin slowly"


If I press and hold the DIAG button as recommended on step 8


Here are my lit leds compared to the expected behavior:

Expected behavior	ME
PSU PWROK (green)	PSU PWROK (OFF)
5V STBY (amber)	5V STBY (amber)
EFI DONE (green)	EFI DONE (green)
GPU OK (green)	GPU OK (green)

This PSU PWROK off is weird to me has I would consider the new PSU as valid since it worked when placed in another Mac Pro.
The CPU tray also worked when placed in another Mac Pro.
I've done the RTC reset, the SMC reset, but no PRAM has the computer doesn't reach this far.

Other leds behavior to be aware about:

• When the power cord is plugged, OVTMP CPUA and OVTMP CPUB briefly flash red, as expected.
• But when the power cord is removed, as far as my eyes can still see, the leds are not flashing while they apparently should too.
• If I replug the power cord within a couple of minutes, the leds will not flash again. I've to wait more time for them to flash.

Thanks a lot in advance for any thought.
Regards.

PSU_PWROK not being lit is a sign that something is wrong with the PSU, but could be a red-herring to think that only the PSU could be defective.

I'd test the PSU with a working Mac Pro. Also, since you tested the CPU tray of the defective Mac Pro with the working Mac Pro, then the backplane is the most probable part to be defective.

The front panel board when shorted also cause the PSU_PWROK not being lit, so, you can disconnect it from the backplane and test powering the Mac Pro shotening the pads to eliminate it.

 

[Tazintosh]

Thanks for the answer @tsialex.
Perhaps my phrasing was not clean english, but I did tested the PSU in another mac (successfully)

This PSU PWROK off is weird to me has I would consider the new PSU as valid since it worked when placed in another Mac Pro.

 

[tsialex]

Install the suspected defective backplane to a working Mac Pro, see if you can power it.

 

[Tazintosh]

And I guess that if it's not working, we'll "just" have to find another backplane?
Or maybe my friend will want to keep the computer as it for spare.
Thanks for all the inputs, appreciated.

 

[tsialex]

And I guess that if it's not working, we'll "just" have to find another backplane?

Short answer, yes.

Long answer, you will need to match the replacement backplane BootROM with the Mac Pro ESN label data, but its critical only if you have software licenses that require the exact same serialization, like several audio related software and some scientific packages.

 

[Tazintosh]

Long answer, you will need to match the replacement backplane BootROM with the Mac Pro ESN label data, but its critical only if you have software licenses that require the exact same serialization, like several audio related software and some scientific packages.

That's a great info! Though I'm not sure he's concerned.