More often than not, there are capacitors on the power supply board that have gone bad. You can tell because their tops will be domed. This is the most common problem with LCD monitors and TVs that I see in my shop.
mine did that to mine was a lg hp flatscreen i just sold mine on here to a monkyd, he just opened a store, he buys them and fixes, hes a cool dude indeed, mine was the blacklight inside the monitor. good luck on yours