Sony KDL-40V2500 Goes on and off.

[Turnip]

Hi folks,
Have one of these where the set comes on normally then runs for two/three minutes then cuts picture and sound with the noise of the PS relay clicking - Led remaining Green.

Couple of minutes later it comes on again, then off again as before - then repeats. Thought maybe PS (1-871-504-11) or even inverter, but thought ask before I waste cash.

Any thoughts ? - Thanks - Chris.