I have this busted Lynx. It doesn't work on batteries because the previous owner left batteries in it for years and they exploded inside it. So I bought a power pack for it, plugged it in and it actually turned on, the music started and I could hear that the game worked after pressing some buttons and hearing the sound effects, but there is no picture at all on the screen. The backlight works, but adjusting the contrast knob has no effect, the screen is blank. After opening it up, pulling it apart and putting it back together, making sure the screen ribbon was firmly in (it reminds me of my Amiga's keyboard ribbon), there was still no picture. Then the whole thing stopped working, possibly from the crappy power socket, hopefully not something else. I've not been able to get it working at all since then, so I'm not sure what the problem with the screen was but maybe it's similar to what has happened in yours.
So, I guess I'm sorry this doesn't help at all, but I share your pain, you're not alone.
Edited by Moya Jackie, Fri Feb 24, 2012 12:48 AM.