In message . com, Steve
writes

I was thinking it was probably the service wot broke it.

Maybe the guy needed a quick PCB swap for another customer...

Owain

I was with the guy at all times and nothing was switched out. During
the service the whole thing was dismantled and put pack together. I
cant believe it is a coincidence that is it now not working. I'll
check the pilot and electrodes first.

Did he disconnect the circuit board?

An intermittent fault became permanent here after a service visit. My
conclusion was that the mechanical force needed to wriggle free the
connector worsened an existing soldered joint problem.

regards
--
Tim Lamb