I have a 35 inch RCA Model F35665. The sound is always on but sometimes the picture goes black either as soon as I turn it on (picture black with sound) or as I'm watching (stays black between 5 and 30 minutes). The entire time that it's black the menu functions work fine and it displays the channel title at the bottom (ie ESPN or FOXN) but the picture has gone. It isn't as though it's black like the TV is off, it produces light, it's just the the picture is dark. Any idea how to repair this television? ANY help would be greatly appreciated for this novice. Thanks.
--Cliff