MP 1,1-5,1 MacPro4,1->5,1 Suddenly Bricked

[nixendra]

Hi Guys,

TL;DR; I suspect to have a bricked MP5,1(4,1). I can unsolder and SPI reprogram the rom. I've access to a MP5,1 with 144.0.0.0.0. My Question is; Is changing the Serial number in the MP5,1 Rom Dump I have enough to make a valid bootrom to be reflashed to my bricked MP5,1(4,1) ?


A few years ago I flashed by MP4,1 to MP5,1. Last year I injected the NVMe into my current bootrom. I stayed under High Sierra for various reasons. The system did run fine for months.

A couple of days ago the system froze and I turned it off. Since then I've tried a few things listed below. Which all make me think that somehow my EFI Bootrom got corrupted (but yet it could be something unrelated) even tho I did not intentionally trigger a OS/Firmware Update

Symptoms:

- The System turn on but doesn't boot. No Video Output
- No Chime, No Caps Lock LED
- Hence PRAM reset not possible (would be useless anyway for what I think the cMP state is in)
- DIAG LEDS -> EFI never turns ON (except briefly at power on)
- I'm somewhat able to Enter "EFI Flash Mode" but only 1 times out of 20 or so
- With my GTX 680 and when I finally reach "EFI Flash Mode" I do get a Video Output gray screen. After a while I've the Question Mark Folder - sometimes it freeze.
-> Not sure if I can flash it a custom rom from a CD from here.

What I did try:

- Read the Technician Manual and follow the recommendation
- Read every threads about this kind of issue or related on MacRumors. Very nice post by @tsialex!
- Remove everything but 1x RAM Module (tried all of them in sequence + combination)
- Try to boot in "EFI Flash Mode" but this only succeed 1 time out of 20
- Payed close attention. EFI DIAG LED is never on.

What I conclude:

- At best my EFI Rom is bricked. At worst it's something else but I've no idea what.
-> If it's that I still don't know how it got corrupted

What I think I could do but I need confirmation and advices:

- I can desolder my FlashRom (SST25VF032B)
- I've a dump from a MP5,1 144.0.0.0.0 (MX25L320SD)
- ??? Change Serial number in my MP5,1 dump and flash it to SST25VF032B ?


Looking forward for your inputs
Thanks in advance!

 

[tsialex]

It's not just the serial number (SSN), but various identifiers (OverrideVersion/Hardware descriptor, SSN, HWC, SON, LBSN/MLB, BD) called hardwareIDs - I wrote about it in detail before.

Desolder the SPI flash, dump it securely, then flash the generic 144.0.0.0.0 MP51.fd, test if your backplane works reliably again - iCloud/iMessage/FaceTime won't work anymore.

If it works, we can probably use your suspected corrupted SPI dump to extract the needed hardwareIDs and reconstruct the BootROM.

 

[nixendra]

Thanks tsialex, sorry I've missed the full thread where you wrote those details. I've seen something from you but not the whole thing.

I'll do as you suggest and post the results!

 

[nixendra]

I've dumped the suspected SPI flash but I didn't had time to burn 144.0.0.0.0 and solder it back yet.

I know that's not the purpose of the exercise - and reflashing is the way to confirm - but there's no way I can check that my suspect_dump is corrupt or not right (UEFITool, some sections to check, checksum ?) ?

Note: I opened it in UEFITool and it *looks* OK (Sections are all there from what I can compare* )
*I've also found my Injected_NVMe image I did last year - so I guess I can also get all HW IDs from this one.

 

[tsialex]

I've dumped the suspected SPI flash but I didn't had time to burn 144.0.0.0.0 and solder it back yet.

I know that's not the purpose of the exercise - and reflashing is the way to confirm - but there's no way I can check that my suspect_dump is corrupt or not right (UEFITool, some sections to check ?) ?

It's a complex procedure to validate a dump since you have to exclude the NVRAM volume, BootBlock and MLB/LBSN sectors, the three parts will differ from the generic MP51.fd. With a injected NVMe module will make it even more complicated.

 

[nixendra]

Got it! Thanks.

Last question before I actually do what you suggest since the first post - If the SPI is not the issue I guess I've real brick, right ?

 

[tsialex]

Got it! Thanks.

Last question before I actually do what you suggest since the first post - If the SPI is not the issue I guess I've real brick, right ?

The brick expression is usually applied to a backplane with a corrupted firmware that once reflashed will work again, if your problem is elsewhere then you have a defective backplane.

 

[nixendra]

So I re-flashed my FlashRom no luck, the EFI LED doesn't light up / no Caps lock.

So I guess the backplane is indeed dead.