[Brian Clark]

Jim, what are the expected voltages on the MJE340 in the CF CCS?
It's really weird. I have found that the heater supply on one channel had incorrect polarity yet that's the one that is working (after a fashion). The other channel, with correct polarity, is dead as a toenail  

Thanks

Brian.

[Brian Clark]

It's OK, panic over
First time I've used transistors for many years. That'll teach me to go paddling in unfamiliar waters  

Brian.