I use my monitor (LCD4010) as a television connected to DirecTV. I also have a dvd player attached. Has worked perfectly. Yesterday, while watching tv, I lost the picture. Sound is still ok. It is not a black screen but is snowy... like an old tv with no antenna hooked up. Any idea what happened? What to do?

SOURCE: problem with plasma tv

Something in the path to drive the other half of the screen has failed or is broken. Need some basic troubleshooting information in order to be any more specific, but I've seen this problem before with NEC plasmas. If still under warranty better use it Good luck

SOURCE: No display

When you get the red and green leds lit it means the screen doesn't see an input signal and has gone to stand-by. That the red led goes off when you reconnect suggests a signal has been recognised by the screen but be very aware that it may not be a good signal. As you are using a PC input I will assume the signal is RGBHV, maybe you have the H and V swapped around? I would try another computer source into the screen.
You say you are using the digital harness, please explain exactly what this is.

SOURCE: No signal with NEC plasma PX-50XM4A

You were right when you called it a monitor, it is a monitor, which means no tuner. To be able to use it as a TV you will need cable box or satellite receiver or something that has a tuner in it.

SOURCE: NEC widescreen tv sound but No picture model no.

if its always 1min. work b4 the picture offf ,check ur power filter capacitors & if only sound comes when power on change ur inverter