rca Scenium 52" tv set wont come on!!!?

Okay i have had this tv for almost 4 years now and never had any problems out of it. well, about 3 weeks ago, it started having problems coming on. the power light will come on, go off, come on, go off, come on and then go off again for the final time, always in this order. it takes a long time to get it to come on sometimes hours. but once i do get it on it will stay on till you turn it off. i have tried unplugging overnight, checking all the parental controls. you name it i have done it. i dont wanna open it up cause i am afraid i will mess something up. Please help!!