MP 1,1-5,1 Mac Pro 5,1 Dual CPU - EFI_DONE, SYS_PG, No Video, Fans Ramp to 100% After Logic Board Replacement

[evnn22k]

Purchased as non-working (no power).


Replaced the backplane/logic board (820-2337-A).

Now:

• SYS_PG = green
• EFI_DONE = green
• 5V_STBY = amber
• Optical drive initializes
• Power LED stays solid white
• Fans stay normal for ~2–3 seconds, then ramp to full speed
• No video from original ATI HD 5870 (Apple Stock card)
• Same behavior with GTX 1050 Ti
• No-RAM test works (power LED flashes with no RAM)
• CPUs swapped between sockets
• CPU socket pins inspected
• New PRAM battery
• Single DIMM in CPU A Slot 1
• Same behavior regardless of whether a drive is installed
• CPU tray connector and backplane connector inspected, no damage

Given that EFI_DONE is lit but POST never completes, would you suspect the PSU or the dual-CPU tray next? Has anyone seen these symptoms?

 

[tsialex]

Two things.

1. Are you absolutely sure that both the CPU tray and backplane are from the same model?
   
   Mix matched backplane/CPU trays combos between early-2009 and mid-2010/mid-2012 cause the fans to run full RPM and full time.
   
   Double check the part numbers, both the backplane and CPU tray require to have the same SMC firmware version, 1.39f5 for early-2009s and 1.39f11 for mid-2010/mid-2012.
   
   SMC firmware is non-upgradeable.
   
2. EFI_DONE can be lit with corrupted BootROMs. Did you tried with Firmware Fail Safe Mode?
   
   
   https://forums.macrumors.com/threads/mac-pro-4-1-flashed-to-5-1-chimes-but-no-boot.2485358/post-34680679

 

[evnn22k]

I forgot to mention that while all of this is happening, the GPU_OK light is flashing green when the DIAG_LED button is pressed. Also, I did a little digging on the Logic Board numbers and serial; the barcode sticker shows the serial number "C070216050NDCVKAU" and a part number of 639-1062. Google says this is a 2009 4,1 Logic Board, which, if that's true, means I was sold the wrong board.

 

[tsialex]

Also, I did a little digging on the Logic Board numbers and serial; the barcode sticker shows the serial number "C070216050NDCVKAU" and a part number of 639-1062. Google says this is a 2009 4,1 Logic Board, which, if that's true, means I was sold the wrong board.

This explains a lot:

C070216050NDCVKAU = early-2009, factory refurbished.

Your Mac Pro is probably not booting because the MacPro4,1 factory installed firmware is not compatible with Westmere Xeons and from factory all mid-2010/mid-2012 dual CPU Xeons are Westmere. The cheapest mid-2010/mid-2012 single CPU Mac Pro still have a Nehalem Xeon from factory.

This explains why even with the EFI_DONE led being lit, you can't complete POST.

You can only install Westmere Xeons to an early-2009 AFTER you cross-flash it to MacPro5,1

 

[evnn22k]

Gotcha, so I'm just going to return it and make sure I'm getting a 2010-model Logic Board. Kinda sucks because they put the listing as "Mac Pro 2010-2012 Backplane/Logic Board Tested Working".