The TV screen just shows AV1, I was trying to turn the volume down and accidentally hit another button which resulted in a blue screen the the letters AV1. How do I get it back to regular TV

SOURCE: No Signal

You will have changed the video/audio input, on your tv, it should be an input button on remote. The signal will either be on AV1, AV2, AV3 Component or HDMI.

SOURCE: Vizio L37

try to go to the menu,then find the words,blue on or off,turn it off,then you will see the changers.

SOURCE: ViewSonic N2750w 27 in Volume turns down by itself

Could be a problem with the down volume button on the tv. the board it's on ir its harness. Check them all. Make sure the volume buttons plastic actuator moves freely and is not stuck.

If these parts are all good, you have a problem on the main board. You may have to trace the control lines as far as you can and check any capacitors along the way. If you have an oscilliscope you can test the lines to see if the up volume is working correctly. If there is noise on it, you might find a bad capacitor if you can trace it back far enough. Schematic helps here.

Of course, make sure nothing is shining on the sensor window on the TV. You might want to scope that line as well (IR sensor line).

If none of that helps, get hold of Viewsonic and find your closest service provider. You can order a main board from them.

Of course, you could try just using the audio out jacks to an amplifier or a surround sound amplifer. Then you would use the remotecontrol for the surround sound system to control your volume.
Bet you were going to buy one anyway right?

SOURCE: Volume and menu does not display

I had this problem on my Aquos (LC-46D62U). It was NOT a hardware problem. I recommend turning off the television. Next unplug the television for 5 to 10 seconds. This resets something for the television. Plug it back in and turn on the television. You should now be able to get your volume and other on-screen displays.

SOURCE: tv screen went blank

sound like the inverter circuit board problem. check & replace back same part# inverter circuit board. hopefully could help!!