I found a friend with a V11 , he broke the plastics that connect the head to the tube so I was going to use it to test my unit, he then he said I could have it so I thought I could perhaps salvage 1 head from 2 heads, great I thought. He got back to me today and said his wife had thrown the head out which is a shame.
He has taken my v8 main unit and head home and tried it with the head from his v11, it doesnt work, are they compatible? would it be safe to assume that its a fault with my unit/pcb?
Tested my head again on the bench, working perfectly from a bench power supply. Only thing I note that there is a high (>3A) startup current.