I'd look at replacing the tcon board at the back of the LCD assembly.
There's currently one on eBay for a reasonable price. It's not mine, but I may also have one later today as I have a 42'' LG ready for disassembly due to cracked screen.
My LG 42LC2D 42 inch TV will not show a picture. The "input" button on the TV and the...
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My LG 42LC2D 42 inch TV will not show a picture. The "input" button on the TV and the remote will not select an input. No picture. The motherboard was replaced a while back. I want my TV to work. I have tried everything I can think of from cable replacement/HDMI to swapping cable boxes. My TV will not work and I don't know why.