MP 1,1-5,1 MacPro 3,1 Back to ElCapitan From BigSur

[Abati1403]

Hi, I bought a MacPro 3,1 "upgraded" to BigSur via OpenCore Patcher. I need to use it with ElCapitan so I removed the OS HD and inserted the HD with El Capitan from a second MacPro3,1 (wich was working perfectly) but the boot gets stuck all the time. I presume the patcher messed up the boot ROM that now is: 9999.999.999.999.999 and the SMC 9.9999.
Is it possible to restore the original boot ROM and SMC? Anything else?
Thanks for your help!

 

[tsialex]

Hi, I bought a MacPro 3,1 "upgraded" to BigSur via OpenCore Patcher. I need to use it with ElCapitan so I removed the OS HD and inserted the HD with El Capitan from a second MacPro3,1 (wich was working perfectly) but the boot gets stuck all the time. I presume the patcher messed up the boot ROM that now is: 9999.999.999.999.999 and the SMC 9.9999.
Is it possible to restore the original boot ROM and SMC? Anything else?
Thanks for your help!

Just erase the disk that OCLP is installed and do a deep NVRAM reset. OCLP is spoofing the values, but the firmware versions are still the same and once you remove the OCLP ESP, everything will be back to the MP3,1 expected versions.

Also check any other disks for OCLP ESPs.

 

[Abati1403]

I put the ElCapitan HD in the Mac and did the intensive NVRAM reset. It worked perfectly!
Thank you very much tsialex!