Hi Bruce, and thanks,
Must have got the Scart lead in upside down as next time I tried, sound a'plenty. Off to find a service manual. Note main boards come as a pair, plenty of tuner boards on Ebay but none of the other with the HDMI sockets. Did the Industry Initialisation - no difference, so it's a toss up whether 'Terminal Unit' or 'Main Unit' is duff. Don't know the history of the set, but guess with a mild lightning flash, it's probably the panel with the aerial socket - Chris.
Later - Downloaded latest Firmware update from Sharp, just in case - Made no difference, but was fun trying. Got 53Mb of service manual from ElektroTanya so won't try upload.
Mentioned 'Cash' to customer, and as most want change from a fiver for a simple job - Declined.
Guess it's one more on the heap - Guess eventually sort as it's a decent 'Non Vestel' set.