I'm betting you still have a bad connection somewhere. Look closely at the cable between the motherboard and the analog board and check the solder joints on both ends. Pushing in on the sides causing the problem to go away is a dead giveaway that there is a bad connection. Always best to take care of problems like this quickly as you can damage other parts by continuing to use it. Also don't overlook the obvious stuff, did the brightness knob get turned down or the pot broken? It sounds funny but I have "repaired" equipment on numerous occasions that have had something switched off/turned down, etc and no actual fault.