How can I turn my sylvania Plasma tv on without going back to standby mode?

42" or 48" Sylvania Plasma Television, do not have model# ,but serial# is V39513122. Turned tv off yesterday,came home yesterday eve.and turned on it did power ON with green light BUT not 5seconds later went straight to STANDBY SOLID RED LIGHT...I have unplugged it for several min. To several hours and it doesn't help....
Thank you