[allybags]

Thought I had cracked it this morning as found a track break between grid of V7B and R68 100 ohm resistor. I have spent all morning inserting a replacement link, but without any success in solving problem. ie everything still as before.
Have tried to reply to contributors as follows:-

WME bill – Yes Anodes at HT rail voltage, so no conduction.

Ronbryan – Disconnected 41 and 42 as suggested with this result. V7A cathode now 53v but V7B cathode now at 300v. I think I would like to take you up on your kind offer, would you like me to come to you?

PJL – with valve removed voltages are as follows:
V7 cathodes both at 0v; Grid volts A at 80v and B at 0v

Craig – both C22 and RV12 seem ok

Soldering iron switched off now until Tuesday. Alan