check the EHT transistor, may be short, check it
out of circuit.
to check the power supply, connect a
60watt 240v light bolb from ground to
the collecter pin were that transistor goes
without the transistor in there, if the power supply
is ok the bolb will light about half brite.
you should have from 100 to 130 volte on
the bolb etc.
if ok put a new transistor in, if the same thing
happens, i suspect the flyback transformer.
john
john