Thanks a lot for your feedback.
My iMac worked perfectly fine before this issue. I upgraded to a new macOS version and everything was still normal. Later I was offered a smaller update, and something went wrong during that installation: the computer froze and the update did not complete.
After that aborted install, I started experiencing System Preferences issues and Bluetooth stopped working. The iMac still booted normally, but I attempted to fix Bluetooth by deleting the Bluetooth plist files. Unfortunately, System Preferences then stopped loading completely, leaving Recovery Mode as the only option to proceed.
I have tested the following:
• Multiple USB wired keyboards — they allow arrow key navigation but no alphanumeric input in the Wi-Fi password field
• Ethernet Internet Recovery fails consistently with error –5101F
• iPhone hotspot is detected, but requires entering a password, which is impossible due to the keyboard limitation
• The iMac’s SSD appears healthy in Disk Utility whenever Recovery does load
• I’m not trying to recover data; the disk can be erased if needed — I only need to reinstall macOS
The problem is that macOS Recovery only offers El Capitan, which cannot install on an APFS volume, and newer Internet Recovery sessions fail before download. On another Mac (macOS Tahoe 26.1), I cannot download Monterey or Ventura anymore because the App Store link opens blank and Terminal fetch commands return “update not found.”
If this were hardware failure, the iMac would not reliably boot to Recovery, detect USB input, or show a healthy SSD. The symptoms align with a corrupted recovery/firmware state after an interrupted update, not a hardware defect.
At this point, I’m looking for a confirmed method to download an official Monterey or Ventura installer without relying on the App Store UI, so I can create a bootable USB for this 2017 iMac.
I would really appreciate guidance from anyone who has successfully restored a similar system recently.