How to Fix Boot Loops on MacBook Pro 2012 during OCLP Install

Resolving Failed Installations on MBP Mid 2012

If your 2012 MacBook Pro fails to complete the installation of Big Sur or Monterey after multiple attempts, the issue is likely a faulty SATA cable or a corrupted EFI partition.

Troubleshooting Steps:

1. NVRAM Reset: Perform a triple NVRAM reset (Cmd+Opt+P+R) to clear any stuck boot arguments from previous failed installs.
2. Wipe EFI: In Disk Utility, format the entire SSD (Show All Devices) to ensure the hidden EFI partition is recreated cleanly.
3. Check SATA Cable: The 2012 13-inch MBP has a notoriously weak hard drive cable. If the install hangs at '12 minutes remaining', the cable is likely failing. Test: Try installing to the SSD via a USB adapter. If it works, replace the internal cable.