I pressed "source" on remote and the screen went black except for "No Signal" in a blue box in lower right corner Ican't get a picture back

That means the Source or Input has been changed to the number 1 HDMI Port and there is nothing attached to it, or if there is a cable box on it, the cable box is turned off. Check that first and then press the Source button on the television remote until you find a signal. You can check the HDMI sockets at the rear of the set and see if anything is plugged in. They are numbered, normally 1 to 3.

hit the source button again that is for your scat press down to 1 HD should get you back on.

To which model television are you referring? It sounds like you either need to change the input method for the TV or just change to a different channel (2 or 4).

You have selected an input on the display that is not getting any signal that the display can recognize. Press the source button either on the set or on the remote until you get a signal.

Unplug the TV. Replug in the TV. If it's still there, you probably have a bad panel. Try changing inputs. These panels are non-repairable.

If you have pip or picture in picture, it may be active and set to a source that has no signal which would give you a blue screen.

call 1800-remotes you can buy a brand new remote

Your backlights power inverter board is what causes this prob. It is a Darfon V144-001.

Air 2 is the source it's looking at for a signal - - where is the signal plugged into? and are you able to change the input or source to look at another?
Bill