Plasma screen help?

i have a 50" high-definition panasonic flat screen TV. with a scientific atlanta HD-DVR BOX. and guess what its SUPER BOWL SUNDAY. Im having people over the house and i have about 8 hours to get this fixed. Tech support for the tv is off on sundays so cant get there help. THe problem is the tv is turninig off on its own after a few mins (this just started today) PLZ HELP