Distorted sound on my LG 42LG50 HD LCD TV. Has been repaired 3+ times under warranty, with no success. LG refuses to replace, since it is now out of warranty, though problem persists beyond the warranty period. Repairs already done include replacement of the main speakers, replacement (X2) of the main board, placing foam in TV to try to stop vibration. None of these attempted repairs worked. I believe this TV to be a "lemon."

What is done is opened the tv up, turned it on and turned it up found where the vibration was coming from, it was loose (rattling) so i stuffed a pair of socks in and it wedged it together, 6 months later Still not a problem, please note (not a recommended solution) but does work !

Ur last chance,might be the power supply board,could have very small amount dip current going through ur tv main Tuner board causes this problem.We might be fishing here,but this is the only logical answer left.Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish power suppply for the replacement.