I have a Hitachi 52" LCD flat screen Model # L47S601 T.V. that suddenly WILL NOT turn on....?

It worked this morning, I turned it off for a couple of hours and when I tried to turn it back on....NOTHING! Could it be a simple "do-it-myself" fix? Maybe a bulb? (is that the right terminology?) If anyone out there thinks this might be the problem, can anyone clue me in on where this (the bulb?) might be, how I go about getting to it, what tools I need and where I get a replacement bulb? Thank you so much!!!!!