The transistor is either the power supply FET or the HOT.
The HOT on most mid 80's up sets have a damper diode
E-C & a resistor B-E. 99.9% dead short when they fail.
Power FET's can dead short D-S or open. The one
board Zeniths had 2 small 'lytics in the PS that caused
int dead or dead. The 2 boarders were big sets so almost
all were done in home at board level til near the end.
For the control board it helps to have one of those 3 foot
long xelite 1/4 drivers. I still got mine but you will have to
pull it out of my cold dead hands.
I will look later today for the manual.
73 Zeno
