I looked at my brothers Mitsubishi 55 inch rear projection tv. All the a/v inputs are not registering. The front of the tv on Input 1,2, and 3 show up blank. Nothing. It wont even say Input 1 on the screen. After taking back off of tv and playing around I found if you tapped on the circuit board it would come on. If you shake some of the wires a little bit it would come on. The compenent side still works. He has his satalite hooked up and it still works fine. Would this be a bad connection? How would I find it? I couldn't think of any tests to try without taking it all apart. Any advise on where I should start?
chris
You have made a good start to finding the bad solder connection.
Next, unplug ac, pull (or slide back and flip up, if possible on your model) the chassis and inspect for cracked solder joints on the bottoms of the circuit boards.
Look closely with a strong worklight and magnifier, at connectors and ic's solder.
Mark every wire you disconnect so there is no confusion when reconnecting.