I've been playing with a broken LG 566 LM LCD screen I got my hands on. I posted about it about a week ago, and I've since replaced all of the caps on the main board with no change in the symptoms. I started poking around on the board checking voltages as best I could by following traces from the power input lines, and I noticed that there are a few caps near the two ribbon connectors that run to the actual LCD panel that have voltages written next to them in the silkscreen. The voltages written are 9.2, 3.3, 18, and -6 volts. The caps themselves are rated well above these values.
Measuring between the positive side of these caps and ground with the unit powered on, I get nothing above 4.5 volts -- does that seem odd, or is there something about the way I'm measuring that would give me false readings? I do have good voltages at the input from the power supply, 2x5v and a single 12v, but since the one visibly bad cap that I replaced in the power supply was on the 12v line, I'm wondering if there is some component on the
12v line of the main board that shorted or went open and is causing problems.If anyone knew where I might be able to find a schematic for this unit that might help me out, I'm by no means a professional tech but I like to learn what I can by tinkering with broken gear... especially when there's nothing to lose, as in this case! All I have is a DMM and some spare time once in a while, but I'm hoping I might get lucky and find one bad part that is the culprit.
Thanks in advance for any help!