Seriously, don’t open your TV. You may make matters worse and much more expensive.
But there are a few things you can do:
If your TV does not come on at all – Try using the power button on the TV itself, perhaps the remote is defective, has drained it’s batteries, or you have a Comcast or universal remote that has lost it’s settings.
Be sure that power is actually on the outlet – Plug in a lamp or other device to be sure that there is power there. Check that the TV plug is plugged in fully AT BOTH ENDS. Often the end of the cable closest to the TV is loose.
Try unplugging EVERYTHING associated with TV system – Cable/satellite box, sound system/ video-receiver-amplifier, video game consoles, and all USB connections. Leave them unplugged for 5 minutes, then plug it all back in and wait 5 minutes before turning anything on. Resetting things are a very common problem that people just do not try and result in a service call.
If your TV comes on but you do not get a picture, but you do get SOMETHING/ANYTHING on the screen – Verify that your cable/satellite box and or your other associated components are also turned on. Sometimes they can get out of sync with each other so if some of your components are off and everything else is on, you may not get a signal. Turn on any powered off components on, MANUALLY. Be sure that your TV input is set on the correct input i.e. TV, video 1, video 2, HDMI 1 HDMI 2 and so on; cycle through them if you are not sure. Remember, if you anything is displayed on the TV screen, it’s probably not a broken television. There are some rare occasions that this is not true, especially if it is an HDMI related input issue.
Are ALL the cables plugged in? – We go on many calls that the color is wrong or there is no picture at all, and it’s just that a cable was inadvertently unplugged or not fully seated. This is most common with component cables, which are red, green, and blue. Check the connections.
Other than the above steps, please do not take apart your TV.