how to fix panasonis TH-42PWD6?

having trouble with the on/off switch. when i turn it on, it starts up but within a second it turns off leaving the red light flashing at 'G'-power on. this has happened before but normally after several tries it comes on,..now ive been at it hours an it still wont turn on. ivr tryed switchin all sockets off at wall an pull plugs out, yet still no difference