For Sony, that's an unusual failure -- sounds like the IR reciever board isn't recieving any IR signal from either remote.
Have you recently changed some of your TV room's bulbs to the compact flourescents? They are notorious for generating lot's of IR, and they can FLOOD the room with so much IR that the little bit of IR coming from the remote can be overcome by the lamps so they won't work -- unless you turn off the lamps.
Let me know if that's the case.
Replace the H2 Board Part Number 1-857-331-21
You should have no problem getting one.
Here is disassembly instructions ---
If you have any questions, just ask
If you are finished, please press the ACCEPT button.
Tips are greatly appreciated !