I have a Sony DVDRW DW-D22A with the BYS3 firmware. Lately, I don’t know why, but my drive will not play DVD’s. It burns CDs, plays CDs, but doesn’t play DVD’s. I’m stumped. I’ve flashed the crap out of the drive, and it’s out of warantty anyways. I figured I’d come here and ask for help. 
Any help would be greatly appreciated.
Thanks in advance.
don’t want to make you unhappy but it might (and i stress the might) be the laser in the drive thats bust. in a dvd burner theres two lasers, one for dvds, one for cds, its possible that the dvd laser has failed and the other one hasn’t, explaining why it can burn/read cds and not dvds.
Well, for instance the drive will play about five seconds of a DVD, then just sit there. Someone on another forum suggested getting a CD-lens cleaner, and trying that.
Probably. When a drive fails on me, it’s never been all-at-once. One of the lasers fails and it’s either no CD or no DVD, the survivor still works (temporarily).
Hope the cleaning works for you though. 