Sony Bravia 32S2010?

My TV switches on ok but as soon as the picture appears it clicks off into standby. Then after approx 10 seconds in switches on again, only to then shut down as before. This power cycling then continues. I have read elsewhere that there are standby light blink codes to aid fault finding, but this does not help - it's not a blink code situation.
Help and advice welcome!
Thanks

Mike
October 2010