I don't know how far you are from an Apple Store but if you're close enough just make an appointment and bring it in. I bought a used 7,1 and started having intermittent booting problems and finally would not boot at all. After checking everything I could do with a lot of help from the people here I brought it to Apple. When they couldn't get it going while I was there, I left it with them and they ordered a new power supply to test with it, at no cost to me. They told me I would only get charged if they had to replace some part and would let me know before they did anything. In the end it wasn't the power supply they tested and was told the motherboard was bad. They wanted $1400 for parts and installation. I only paid $1200 for the computer and told them I could buy another one for that price. The Genius suggested find one with only an 8 core and put my 16 core in it and if I had any trouble getting it going to bring it in and they would help. So thats what I did. I bought a rack 7,1 with an 8 core 512 hard drive 96 ram and put processor, hard drive and added ram into the rack. It all worked without their help, but they were willing to help me even though I bought none of it from Apple.
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MP 7,1 Mac Pro 7,1 will not boot after Tahoe 26.3 update
- Thread starter Fastsavage
- Start date
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Well after weeks of trying to get it running (not full time 🙂 ) IU finally caved and took it to my local Authorised Apple Repairer....
It's in the queue to be accessed....
It's in the queue to be accessed....
Update so far........
Notes from Tech.
Powered up machine. It booted to the flashing folder indicating nothing could be found to boot from. Restarted to diagnostics. Nothing on screen. Tried several restarts with the same issue consistent with the reported fault. Machine does go into DFU mode. Tried a Revive with still the same issue. Removed cover. Unit has a Promise RAID installed. Possible issue with the new Firmware not being compatible with the RAID. Removed the RAID starting to the flashing folder consistently. Checked online about the RAID. There was a suggestion that the RAID should be in slots 1 and 2 rather than the 3 and 4 it currently is. Swapped the RIAD and Graphics card over. Consistently starting to the flashing folder at the moment. Now attempting to get to Recovery to install a fresh OS. [5/3/26 13:47 JH] Unit then returned to no video and now seems consistent in that. Removed RAID again. Same issue. Possible RAM fault. Minimised down to one module. Same fault. Either Video card or logic board. Trying a Restore without the video card installed. [9/3/26 8:41 JH]
Note from me [Raid and Vega Pro haven't been moved since installed by Apple]
Notes from Tech.
Powered up machine. It booted to the flashing folder indicating nothing could be found to boot from. Restarted to diagnostics. Nothing on screen. Tried several restarts with the same issue consistent with the reported fault. Machine does go into DFU mode. Tried a Revive with still the same issue. Removed cover. Unit has a Promise RAID installed. Possible issue with the new Firmware not being compatible with the RAID. Removed the RAID starting to the flashing folder consistently. Checked online about the RAID. There was a suggestion that the RAID should be in slots 1 and 2 rather than the 3 and 4 it currently is. Swapped the RIAD and Graphics card over. Consistently starting to the flashing folder at the moment. Now attempting to get to Recovery to install a fresh OS. [5/3/26 13:47 JH] Unit then returned to no video and now seems consistent in that. Removed RAID again. Same issue. Possible RAM fault. Minimised down to one module. Same fault. Either Video card or logic board. Trying a Restore without the video card installed. [9/3/26 8:41 JH]
Note from me [Raid and Vega Pro haven't been moved since installed by Apple]
Regulus67
macrumors 6502a
The flashing folder is normal, after a DFU restore. Indicating no OS installed.
I have my RAID installed in slots 3 and 4 as well. Never read it should be in the first slots.
An issue with the new firmware is worrying, if it is correct.
I have my RAID installed in slots 3 and 4 as well. Never read it should be in the first slots.
An issue with the new firmware is worrying, if it is correct.
I did find this actually so thought he might be onto something but….
About the Promise Pegasus R4i MPX RAID storage module for Mac Pro (2019) - Apple Support (NZ)
Learn how to install and use the Pegasus R4i with your Mac Pro (2019).
Regulus67
macrumors 6502a
How peculiar. Wonder why it would improve performance.
I will run a speed test in a couple of weeks, when I am back home again. Not that I need improved performance from what is just a huge files storage. The internal 4TB SSD gives the high performance I could ask for.
But now I am curious 😂
Graphics performance is way more important.
I will run a speed test in a couple of weeks, when I am back home again. Not that I need improved performance from what is just a huge files storage. The internal 4TB SSD gives the high performance I could ask for.
But now I am curious 😂
Graphics performance is way more important.
Bit of an Update - I picked up the Mac from the repairer. Looked at it for a bit and decided to ring Apple Support again. I said I couldn't understand how it was running one minute, then did an update and wouldn't go again - they said the update could have exposed a hardware issue.... Hmmmm not sure about that..... But anyway, I explained that it was a very expensive machine and should have lasted more that 5 1/2 years...
So they are going to pay to have it repaired under our "Consumer Laws" BUT only limited to Logic Board, CPU, GPU and RAM (not sure what else is left of any significance...
There is a lot of criticism of Apple but on this occasion..
Good on you Apple, if you are looking I really appreciate the effort and excellent customer service.
So they are going to pay to have it repaired under our "Consumer Laws" BUT only limited to Logic Board, CPU, GPU and RAM (not sure what else is left of any significance...
There is a lot of criticism of Apple but on this occasion..
Good on you Apple, if you are looking I really appreciate the effort and excellent customer service.
Ok - so its fixed - here is the update from the Tech
Logic Board received and installed. Powered up and ran System Configuration. All OK. Now running diagnostics. MRI Tests reported a configuration and verification test but not an actual memory failure. Investigating further.
Installed Tahoe. Booting OK to the setup screens. Restarted to Full Diagnostics. They also reported a memory configuration error but saw the expected total of 192GB. Confirmed memory is installed in correct sockets. Created a Test user.
Memory is seen and all DIMM's show as OK. Only one of the DIMM's is showing a serial number of the DIMM (maybe the cause of the configuration error?).
Installed the Pegasus RAID. Drives are seen and showing 24TB of storage. Installed the Pegasus/Promise app. Drives are seen with the app. Machine continues to boot and work as expected.
Suspect the initial cause of the fault was a Firmware update that didn't install properly and put the machine into a state that could not be recovered from.
I also noted that Apple updated iBridge on 24th March 2026 so I wonder if that was to fix the above?
Logic Board received and installed. Powered up and ran System Configuration. All OK. Now running diagnostics. MRI Tests reported a configuration and verification test but not an actual memory failure. Investigating further.
Installed Tahoe. Booting OK to the setup screens. Restarted to Full Diagnostics. They also reported a memory configuration error but saw the expected total of 192GB. Confirmed memory is installed in correct sockets. Created a Test user.
Memory is seen and all DIMM's show as OK. Only one of the DIMM's is showing a serial number of the DIMM (maybe the cause of the configuration error?).
Installed the Pegasus RAID. Drives are seen and showing 24TB of storage. Installed the Pegasus/Promise app. Drives are seen with the app. Machine continues to boot and work as expected.
Suspect the initial cause of the fault was a Firmware update that didn't install properly and put the machine into a state that could not be recovered from.
I also noted that Apple updated iBridge on 24th March 2026 so I wonder if that was to fix the above?