The LDW-811S was the worse burner i ever owned.
Disc burned with that drive were only readable in that drive.
I ended up re burning almost 70 data dvd because of that POS
it was also the last Lite-on drive I ever owned
and samsung & LG all make much better products.
Are you sure the Recorders are worth repairing ?
Is their something special about the recording feature’s on those that any set top recorder won’t do ?
maybe this would make a decent replacement
just trying to help