My lg Lm3700 has sound but no picture but the tv screen is bright not dark whats the problem and is it a eady fix

[charlottep320]

How to fix my led Lm3700 tv no picture but has sound and bright screen

 

[paulchezter]

Is this connected to another device such as speaker or audio receiver? If yes, please make sure that cables are plugged in correctly. If not, check with a local repairman for a possible issue with the main board and ask for further diagnosis.