To all those who lost BD playback –
Boot into recovery mode and choose the 3rd option "Restore File System". This will restore BD playback.
And no, I'm not kidding.
However you probably need the untouched DRL files from when you lost playback, I wouldn't suggest doing it if you tried to restore playback with DRLtools and failed (unless you have a backup of the original DRL files ofcourse).
Also, I can't guarantee that it will work if you have replaced and remarried a new BD controller board after losing BD playback.
I restored my playback after remarrying a new drive, however I had copied backups of DRL files from the unit that drive used to be in. I did not try doign it with the DRL files that were originally on the unit with the BD missing. If anyone is in such a case and trys this out, let me know
Thanks to zecoxao from gitbrew IRC for pointing this to me, and sorry if this is already known, however I haven't seen this mentioned anywhere.
PS3 Slim CECH-3004A 160GB
PS2 Slim SCPH-70004 - FMCB 1.8b