Power board inside the LCD or Plasma Tv my friend.
Based on the brand, whatever it is in about three to four years you can expect a tv to do this.
It`s the most common part to fail, because of where the power board is placed in the tv it`s self.
The good new is for most, all you have to do is open the back of the tv up and locate the power board number found on the board it`s self and the tv model number along with the size of the lcd screen it has.
A quick search on e-bay and you can get most from about £20 upwards.
Of course it`s down to you if you think it`s worth fixing.
The cheaper option is to open the tv, look at the power board and look for any faulty capacitors on the power board.
Typically you know when a capacitor is goosed because it is domed on the top, or has a sticky brown fluid leaking out of it.
If you replace the ones that look damaged, there is a good chance it will fix the LCD tv and the screen will work again showing a picture.
For a few new caps depending on the size it will cost you in the region of about £5.
Oh and you need a soldering iron, and be half decent at soldering also.
If your very unlucky depending on the error it can be the inverter board that`s given up on the tv.
They cost a bit more due to them being high voltage parts. Not something you want to mess with.
In fact if memory serves me right 5 blinks are an inverter error on sharp lcd tv`s I think.