Thanks Jordan,
Set actually went off once today, and came back on after a few seconds with no red flash, just green led off then on again, with a click of the relay. Have a main board feeling, as my last Sony with the problem, was the FEE (DVB) board being duff, this later one uses just one SSB.
Main board is 1-857-345 and Power 1-878-988-41 (APS-243) - Chris.
Later 7/4/15 - Replaced P/S, set seems OK - Now got another one in, same fault.