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mackcat

macrumors member
Mar 3, 2011
54
14
It's not unheard that in some cases the failed SPI flash is completely dead, but most times it's just a sector that fails and most of the contents can be read by an external SPI flash programmer and the needed information extracted.

While a failed dump can't be used to flash a replacement SPI flash memory or a MATT card, it can be very helpful for a firmware engineer to repair your BootROM.

It's not a job for someone without experience, it's extremely complex to do it and involves a lot of EFI 1.10 specific knowledge (like how to create the space reference of each variable in the correct endianness and know how to make the checksums and free space indicators), but a firmware engineer with Mac Pro knowledge and a lot of different reference dumps can recreate your BootROM from just the ESN and MLB labels - even if the SPI is completely dead.


You have to make some calculations to see if a repair or a MATT card is not the best option, backplanes are becoming scarce, the going price right now on eBay is around 2x of 2018/19.

For people outside the continental US, repairs are more economical. For people in the EU, MATT cards are a no-brainer.

Thanks, I really appreciate you taking the time to explain all this to me. I'm in the US, so it looks like a replacement backplane starts at a little over $100 on eBay, while a MATT card is ~$75 shipped. Would I be correct in thinking that the cost of a board repair or a MATT card, plus paying a firmware engineer (assuming I could find one) to repair my corrupted BootROM, would likely be greater than that of a replacement backplane?

As long as I purchase the correct year backplane, there wouldn't be any issues due to it having a different serial number, would there?

EDIT: I just bought this backplane for a little under $75 shipped https://www.ebay.com/itm/APPLE-MAC-...9-631-1009-BACKPLANE-LOGIC-BOARD/324553246825
 
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tsialex

Contributor
Jun 13, 2016
13,454
13,601
Thanks, I really appreciate you taking the time to explain all this to me. I'm in the US, so it looks like a replacement backplane starts at a little over $100 on eBay, while a MATT card is ~$75 shipped. Would I be correct in thinking that the cost of a board repair or a MATT card, plus paying a firmware engineer (assuming I could find one) to repair my corrupted BootROM, would likely be greater than that of a replacement backplane?

As long as I purchase the correct year backplane, there wouldn't be any issues due to it having a different serial number, would there?

EDIT: I just bought this backplane for a little under $75 shipped https://www.ebay.com/itm/APPLE-MAC-...9-631-1009-BACKPLANE-LOGIC-BOARD/324553246825
You will need to do all the song and dance of firmware updates if the board you bought is not on current one, remember that if the replacement still have a MP4,1 firmware it won't power on with a Westmere Xeon (W36xx, E56xx, L56xx, X56xx) installed on the CPU tray until the firmware is cross-flashed to MP5,1.

Btw, it's possible to modify the firmware of the replacement board to match the hardwareIDs of the case, but it's not a problem having it different. Some people OCD will be triggered, but it's just that.
 
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tsialex

Contributor
Jun 13, 2016
13,454
13,601
Thanks for all the expertise @tsialex.
Will my ROM dump go out of date with subsequent firmware updates? It seems a bit like 144.0.0.0.0 is the end of the road for the cMPs.
It's an already obsolete Mac, last firmware update was with 10.14.5, Apple won't release anything for MP51.
Do I need to do new ROM dumps in future?
If you have one that garbage collection is working, no need.


 

mackcat

macrumors member
Mar 3, 2011
54
14
You will need to do all the song and dance of firmware updates if the board you bought is not on current one, remember that if the replacement still have a MP4,1 firmware it won't power on with a Westmere Xeon (W36xx, E56xx, L56xx, X56xx) installed on the CPU tray until the firmware is cross-flashed to MP5,1.

Btw, it's possible to modify the firmware of the replacement board to match the hardwareIDs of the case, but it's not a problem having it different. Some people OCD will be triggered, but it's just that.
Thanks, that makes sense. I did indeed upgrade to an X5680, so it looks like I’ll have to pop the old processor back in temporarily.

Just in case I want to go a different route and dump the bootROM, have it repaired by a firmware engineer, and have it flashed to a MATT chip, where would be a good place to find someone like that?
 

mackcat

macrumors member
Mar 3, 2011
54
14
So, something very strange just happened. I bought the replacement backplane, received it, but haven't installed it yet. I wasn't looking forward to having to temporarily install the original processor. The computer has been unplugged for about a week.

Now, I just bought a Mac Pro 3,1 for $20, for parts. It doesn't so much as make a sound. It came with an HD 5770 graphics card, which I wanted to test. So, I took it out of the 3,1, removed the GT 120 from my 4,1/5,1, and installed the 5770 in it. All I expected was to see the boot screen, as I thought it was likely the Apple version of the card. To my great surprise, it not only showed the boot screen, it booted into macOS with no issues!

Now, I'm really wondering what is going on. Is it possible that somehow, it was able to boot once, even though the chip is still damaged? Or could it have been something to do with the GT 120 graphics card? (Which seems unlikely, as it still booted fine into Ubuntu).

Now, I want to do a ROM dump with ROMTool, but unfortunately, SIP is on. I will have to reboot it to turn it off, which risks it potentially not being able to boot again if the chip really is bad. What do you suggest?

Thanks!
Ben

EDIT: I was able to successfully reboot into recovery, turn off SIP, reboot back into macOS, and dump the ROM. Somehow, the computer seems to be functioning perfectly now ?
 
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14UG

macrumors member
Nov 11, 2010
68
40
Scotland
So, something very strange just happened. I bought the replacement backplane, received it, but haven't installed it yet. I wasn't looking forward to having to temporarily install the original processor. The computer has been unplugged for

Now, I just bought a Mac Pro 3,1 for $20, for parts. It doesn't so much as make a sound. It came with an HD 5770 graphics card, which I wanted to test. So, I took it out of the 3,1, removed the GT 120 from my 4,1/5,1, and installed the 5770 in it. All I expected was to see the boot screen, as I thought it was likely the Apple version of the card. To my great surprise, it not only showed the boot screen, it booted into macOS with no issues!

Now, I'm really wondering what is going on. Is it possible that somehow, it was able to boot once, even though the chip is still damaged? Or could it have been something to do with the GT 120 graphics card? (Which seems unlikely, as it still booted fine into Ubuntu).

Now, I want to do a ROM dump with ROMTool, but unfortunately, SIP is on. I will have to reboot it to turn it off, which risks it potentially not being able to boot again if the chip really is bad. What do you suggest?

Thanks!
Ben

EDIT: I was able to successfully reboot into recovery, turn off SIP, reboot back into macOS, and dump the ROM. Somehow, the computer seems to be functioning perfectly now ?
Glad to hear it. You are in the same situation as me. Get the ROM dumped, check your dump has the right garbage collection and flash it to the new chip.
 
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mackcat

macrumors member
Mar 3, 2011
54
14
Have you ever seen something like this, where the Mac Pro exhibits symptoms of the chip failing, and then starts to work again, @tsialex? Ever since I switched out the HD 5770 for the old GT 120, the computer has booted every single time. I did a ROM dump, just to be safe. I'm just wondering what could have happened.

Thanks,
Ben
 

tsialex

Contributor
Jun 13, 2016
13,454
13,601
Have you ever seen something like this, where the Mac Pro exhibits symptoms of the chip failing, and then starts to work again, @tsialex? Ever since I switched out the HD 5770 for the old GT 120, the computer has booted every single time. I did a ROM dump, just to be safe. I'm just wondering what could have happened.

Thanks,
Ben
Sometimes is possible to unstuck a failing sector and get some more months of SPI life.
 
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mackcat

macrumors member
Mar 3, 2011
54
14
Sometimes is possible to unstuck a failing sector and get some more months of SPI life.
Thanks, I was wondering if it could be something like that. I’m guessing it would be wise for me to invest in a MATT card flashed with my ROM dump if I want to continue using this backplane without getting the chip itself replaced.
 

14UG

macrumors member
Nov 11, 2010
68
40
Scotland
Q: I have three macOS 10.14.6 installs in my cMP. If I run security updates on each one - am I wearing out my SPI flash 3× faster than if I was only keeping one OS up to date?!?!

Thanks in advance!
 

tsialex

Contributor
Jun 13, 2016
13,454
13,601
Q: I have three macOS 10.14.6 installs in my cMP. If I run security updates on each one - am I wearing out my SPI flash 3× faster than if I was only keeping one OS up to date?!?!

Thanks in advance!
Yes.
 

Alan Young

macrumors newbie
Jan 20, 2004
13
14
tsialex,
I have dumped my boot rom and checked the free space as you had shown. The result is the Full size on mine is 6000h (24576). As this is quite low, I am getting nervous. I just replace the backplane with one from eBay because my last one won't boot. You helped me out in a previous post.
So now I have the file from UEFI tool how to get it to you to repair it, and how do I pay you?

Thanks,

Alan
 

tsialex

Contributor
Jun 13, 2016
13,454
13,601
tsialex,
I have dumped my boot rom and checked the free space as you had shown. The result is the Full size on mine is 6000h (24576). As this is quite low, I am getting nervous. I just replace the backplane with one from eBay because my last one won't boot. You helped me out in a previous post.
So now I have the file from UEFI tool how to get it to you to repair it, and how do I pay you?

Thanks,

Alan
Check your PMs, I've sent you the instructions. Please follow it to the letter and I'll check your BootROM image.
 

Alan Young

macrumors newbie
Jan 20, 2004
13
14
tsialex,
I just read the PM. Thank you very much. I will get everything together and get it sent to you. I'll breath a little easier once this Achilles heel of the Mac Pro is replaced.
Thanks,

Alan
 

fzJNotIBOxgnbqejSeVCvJScL

macrumors regular
Jun 16, 2021
116
49
On the BootROM thread you can see exactly step by step what I did, including my dumb mistakes. It's all there, follow the link on my previous post here.

Buy a ch341a kit, plus a MXIC MX25L3206E. Use flashrom to program it. After you get your Mac Pro booting again and you confirm it working, you can hire someone to reconstruct the firmware, since when you flash the generic MP51.fd you can power it on but no hardwareIDs are present and you can't login to iMessage/FaceTime/iCloud.
Any recommendations on who to hire to reprogram the BootROM?
 

dmtr

macrumors newbie
Nov 14, 2023
7
0
@tsialex what is the option to have a new chip without soldering? is there some kind of SOIC8 bed for the new chip?
 
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