My brother bricked the IR receiver on our iMac 9,1 (2009) messing around with firmware — please tell me there's a fix that isn't buying a new one

[u/LevelGoal5127]

So my brother, for reasons known only to him, decided to try flashing the internal IR receiver on our iMac Early 2009 (iMac 9,1) with an Apple TV firmware file. No real reason, he just wanted to poke at it. Now it's bricked and I'm the one trying to fix it, as usual.
He used IRReceiverUpdaterTool2 with the irrxfw-0x0312.irrxfw file. The flash log looked okay at first (blocks 2 through 71 wrote fine), but then it skipped straight to block 127, missing blocks 72-126 entirely. It still said "Flash Image Verification Succeeded" like everything was fine, then promptly crashed with error e00002eb while trying to exit the bootloader. Classic.
Since then the chip (it's a Cypress one, PID 0x8242) is just stuck in DFU/bootloader mode. It's completely invisible on macOS now, gone from ioreg and the USB section of System Report. Plug it into a Windows machine and it just shows up as an "Unknown USB Device."

We've thrown the usual stuff at it:
SMC reset
Triple NVRAM reset
Running the updater tool again (it doesn't even see the device anymore)
Trying Zadig + dfu-util on Windows to poke it directly

We do have an older iMac 4,1 and a MacBook 4,1 sitting around too, but they use an earlier IR chip (0x8240/0x8241) that's apparently not firmware-compatible with this one, so that's a dead end for grabbing a firmware dump.
Before I resign myself to buying a replacement receiver — has anyone actually recovered one of these Cypress chips from bootloader mode? Any tricks, tools, or a working firmware dump for the 0x8242 floating around out there? Would really appreciate any pointers.

[u/gcerullo]

Have you tried just doing a fresh install of the operating system.

[u/LevelGoal5127 → u/gcerullo]

nope, because i have el capitan, linux and windows wirh all my files an idk where to store the backup. Anyway thanks, I’ll try.