We have a new Proscan 40" LCD/HD TV. It works fine with RCA cables attached between the Verizon FIOS box and the TV. When we changed to HDMI cables so we can get the high def, then the tv works beautifully for about 20 seconds before the entire screen goes to green. We can still hear the audio but the screen is totally green. Any suggestions?

Televison & Video - Proscan - PS50700 50" Rear Projection Television