I made up the K8060 kit, took great care and still managed to get T5 and T6 swapped over with each other. I put the (75W) bulb in series and switched on - the light stayed on. Now, after putting T5 and T6 right, voltage at the +40V and -40V points was only about 7V. Almost nothing at the 9V point. The light still stays on.
Have I fried all the transistors, or only some of them? I know you suggest replacing all semiconductors at once, but if I can avoid replacing the big TIPs then I will.