MP 1,1-5,1 (Mac Pro 4,1 -> 5,1) Mac Pro won't boot (Chimes, no display, shuts down after a couple moments)

[Macropyre]

Evening. I have a dual CPU Mac Pro 4,1 that ran Snow Leopard, flashed to 5,1 to prepare for a CPU upgrade, installed El Capitan and stopped for the day there. Booted the next day, chimes, and PC shuts off after a small moment.

Tried it out after doing some more research (NVRAM/PRAM/SMC resets) to no dice.

Specs as pictured:

Any advice would be appreciated in the matter. Thanks all.

 

[tsialex]

Remove the mains power cable from the PSU, remove the RTC battery, reconnect the mains power cable, power on without the RTC battery and see if you can at least get the grey screen. If so, your BootROM is corrupt.

Also check if the EFI_DONE DIAG led is lit when you press the DIAG button.

 

[Macropyre]

Did your instructions and it booted, saw a progress bar but did not catch text, stuck on a black screen right now.
Hard drive El Cap is installed in is also failing. The waiting games continue.

Pic of diagnostic LEDs attached.

 

[tsialex]

You are hiding the EFI_DONE LED with the screwdriver.

You just confirmed that the BootROM is corrupt, you will gonna need a BootROM reconstruction service. I'd install ElCap with another Mac to a sure working drive, then try to boot the Mac Pro with it. Do not try to install anything with the Mac Pro as is, you gonna brick it definitively.

 

[Macropyre]

Apologies, here's a better picture.

I will see to installing El Capitan on another drive, but ashamedly this is my only Mac.

 

[tsialex]

Apologies, here's a better picture.
View attachment 2307820

EFI_DONE is lit, so, it's the NVRAM volume that is toast.

Btw, you should clean your Mac Pro internally, accumulated dust + humidity is conductive and makes havoc over time.

I will see to installing El Capitan on another drive, but ashamedly this is my only Mac.

I'd avoid that, but if you have no alternative…

 

[Macropyre]

Would buying a replacement board work with these, once swapped out?
Will I have to still be weary of BootROM problems in the future?

 

[tsialex]

Would buying a replacement board work with these, once swapped out?

Sure, a replacement early-2009 backplane would work.

You have to be aware that your replacement will have the same problem, it's a 13 to 14 years old cross-flashed Mac Pro. All cross-flashed early-2009 Mac Pros brick over time because the NVRAM volume have a very different layout than what the MP51 EFI expect to find, the only solution is a BootROM reconstruction service.

Will I have to still be weary of BootROM problems in the future?

Yes, like I've wrote above, the different design of the NVRAM volume is incompatible and fails overtime, usually right after updates or macOS installs (when the NVRAM primary VSS store is heavily used).

 

[tsialex]

Forgot to explain on thing, when you power on the Mac Pro without the RTC battery, the PEI firmware bypass the NVRAM, that's why you got it "working" again, but the NVRAM volume corruption is still there.

When you install the battery back, the problems will be back.

 

[Macropyre]

Btw, you should clean your Mac Pro internally, accumulated dust + humidity is conductive and makes havoc over time.

Don't worry, this was a dust bunny nest before. I wiped down most surfaces but haven't done all, still waiting on some cleaning parts.

Looks like El Cap booted normally! But I know I'm on borrowed time. Will likely buy a backplane if I can but since we got a boot started is there a way to try and save this old lady? How much would BootROM reconstruction hold me back?

 

[tsialex]

…since we got a boot started is there a way to try and save this old lady?

You will need to install Mavericks, with anything newer you need to disable SIP to dump the BootROM, which you can't do as is.

Mac OS X 10.9 Mavericks Installer : Apple, Inc. : Free Download, Borrow, and Streaming : Internet Archive

This is the installer for OS X 10.9 Mavericks. The installer was downloaded directly from the Apple App Store. Please select Mac OS X Disk Image when...

archive.org

How much would BootROM reconstruction hold me back?

I'll send you a PM with instructions, service fee and turnaround time.

 

[Macropyre]

Right now I'm cloning the drive to a spare Samsung 860 Evo.

Will follow through on your PM momentarily after disabling SIP, taking the pics etc.

 

[iclaudius54]

Hey there tsialex, I'm having the same issue. Mine is a modified 4,1 that's flashed to a 5,1 with OCLP on it. I just updated the OCLP and my machine is suffering the same issue. It takes a bit more to shut down, maybe like 20 seconds. Where is the NVRAM volume located? I have OS on an nvme drive and need to absolutely keep it and get it back up and running. You can PM me.

 

[tsialex]

Hey there tsialex, I'm having the same issue. Mine is a modified 4,1 that's flashed to a 5,1 with OCLP on it. I just updated the OCLP and my machine is suffering the same issue. It takes a bit more to shut down, maybe like 20 seconds.

Still power on all times?

Where is the NVRAM volume located?

Inside the Mac Pro BootROM image, store inside the U501 SPI flash memory of the backplane.

I have OS on an nvme drive and need to absolutely keep it and get it back up and running. You can PM me.

I'll send you a PM.