LG42PC1D power problem

[Turnip]

Hi folks,

Have one of these where on connecting mains nothing happens. Mains fuse is OK and I note that S/by +ve supply seems to be directly fed from mains bridge via some series thermisters across a relay and a couple of series diodes.

Is there any common cause of probs  - ?  Chris.

Later - S/by HT feed resistor R510(10 Ohm S) O/C - suspect U501(STRW6251) £5.99+ from Nikko.  Power board 68719PT299A