Can you check input through the AV3 (VGA) port?
I’m having the faint hunch that maybe the THS7353 or TVP7002 crapped out. Only conjecture at this point, of course.
If AV3 gives you a signal, that’d close down on the possible errors on that side.
You might want to contact the guys that own this place (if you bought it here) for support, I’m not associated with them. 😉