Resolved Mac Pro 4,1 - > 5,1 not booting into macOS, stuck at Apple loading screen

[ayr_07]

Hey guys,

I have an OCLP Monterey Mac Pro 4,1 - > 5,1 with the latest BOOTROM. All was working fine till the last month. But then it started having delayed boots after the chime. Initially it was taking about 10-15 min to boot into macos and now it just stopped booting.

What I have already done to troubleshoot are the following:
1. Reseated all the RAMs, they seem to be working fine, no red led anywhere.
2. Cleaned the Mac Pro fully from inside
3. Installed the Mojave OS ssd after removing all the other drives, installed the stock GT120 GPU. Turns out the the loading into macOS has become really slow for reason. Check the screenshot attached. Once the loading bar is at 100%, it just stays stuck forever.

Any tips to troubleshoot? Thanks in advance.

 

[Borowski]

Try again with RTC battery removed.

 

[Macsonic]

@ayr_07 I had the same problem similar to yours a few months back. The same symptoms of the progress bar getting stuck forever after 100%. Though not sure if this issue is the same issue you're having at the moment. Found out it was a permissions problem. Booting to a different drive that was booting fine, right-clicking on the problematic dirve, the permissions on the problematic SSD drive was set to "Read Only". The fix I did was to set the permissions as "Read and Write" and that fixed the problem. I can then boot at normal, fluid speed with the SSD drive that wouldn't boot earlier.

 

[Macschrauber]

Does verbose boot shows something useful before?

 

[ayr_07]

Try again with RTC battery removed.

Thanks for the suggestion, I replaced the battery and now it's back to normal.

Thanks everyone for the suggestions.