No red from the lens usually indicates a bad lens, bad CXA1082 chip or bad traces from the CXA1082 chip to the D78C chip.
Dealing with these issues is a horrible process trying to track down the actual problem. It's taken me many tries to fix DUOs with these issues.
When it is out of my league, I send some of the chip issue systems I get to thesteve to repair because he has more experience with it than I do. Unfortunately he is super backed up with repairs right now and isn't taking on any more work.