Reviews, reviews, reviews...

Question: Picture goes black - please help!

Hi folks,
I've got a new LG 32-inch LD350 TV that's had some picture trouble. It went black not longer after we bought it and spent a month in the repair shop. Now, it turns on and the "TV" tag appears at the top, but it flickers after a few seconds then goes black. I unplugged it for a few days, and the picture returned. But after I connected it to a PC with a DVI cable, it started to go black again after a few seconds, even when I left the TV unplugged for a few days. Does anyone have any advice?? Thanks so much!