Tv switches on but no picture

try switching on tv point remote at the tv pressing the menu/exit button and holding for 10/20 seconds hope this works for you

It sounds that the front panel controls are locked with your tV. You have to unlock it first, if you want to change its input selections. If you cannot select the inputs by using the remote control [I thing you are using a universal remote control], setup the remote control with an other setup code. All codes to remote control won't work with some functions. You have to search and select, which code give maximum functionality with your TV.

Hello
There is a infrared light sensor inside the TV which detects the infrared rays emitted from the remote control, when we press each button on the remote control. If this sensor has got damaged, the set won't respond to any remote control handset. The sensor can be located just behind the infrared sensor window at the front panel of the TV. To access it, you have to open the TV. It is a three terminal component, will be soldered diretily to front panel circuit board, of with the main baord itslef. Will look somewhat brownish black in colour. There are so many types can be seen . Just look what type if fitted with your TV.
See some models infrared sensors. Check out which type your TV has.

TV won't turn on • Press the TV button. Make sure the TV is plugged in.• Check the wall receptacle (or extension cord) to make sure it is "live" by plugging in something else.• Something might be wrong with your remote control. Press the POWER button on the front of the TV. If the TV turns on, check the remote control solutions on page 26.• The front panel controls may be locked (disabled). Use the remote control to unlock the front panel controls by selecting the Lock Fr. Panel in the PARENTAL CONTROL menu and press OK (box won't have check mark).Buttons don't work
• If you're using the remote control, press the TV button first to make sure the remote is in TV mode.• The front panel controls may be locked (disabled). Use the remote control to unlock the front panel controls by selecting the Lock Fr. Panel in the PARENTAL CONTROL menu and press OK (box won't have check mark).• Unplug the TV for two minutes and then plug it back in. Turn the TV on and try again.TV turns off unexpectedly • Sleep timer might have been activated. Go to page 24 for instructions.• KidPass might have been activated. Go to page 21 for instructions.• Wake-Up timer turned on the TV and no remote or front panel buttons were pressed for two hours.• Electronic protection circuit may have been activated because of a power surge. Wait 30 seconds and then
turn on again. If this happens frequently, the voltage in your house may be abnormally high or low.
• Unplug TV. Wait five minutes. Plug it in again.

this is looking like a common LG problem our tv started doing this tonight

The set may have defaulted to a front panel lockout. To defeat that on the front of the set hold down the MENU button for 15 seconds and see if it will then power up. I know that doesn't solve the problem with the remote but one step atta time. These sets are prone to leaky switches on the control panel and when that happens the micro cannot accept two different commands at the same time. That could be why the remote is not working.

waynejman, I have the same exact problem, can you tell me what your outcome was?

Sounds like power supply switch needs to be changed to normal setting. If you are comfortable with electronics i will talk you through it if not you will need a tech or back to cosco it goes if you have a warranty.

Bad volume down tactil switch? Remove suspect switch and see----

the channel down button is stuck on, you need to replace this switch internaly to the set.