Portable DVD player

[Dave_B]

I have a Venturer PVS1951 portable DVD player. I had to open up the case to fix a mechanical problem with the disk holder (now fine) but now I don't have a signal coming out of the two connectors for either of the twin LCD screens - no power, no audio, no video. If I plug headphones directly into the unit itself I get perfect audio output from CDs or DVDs. There are also headphone sockets on the LCD screens, but they are dead. I've been over the circuit boards and connections a few times and I can't see any problems. The screens were fine previously, so I guess the problem isn't there.

Any ideas? Thanks in advance for any help.