The conv board from your other set may be the same.
If not the IC probably are. If you swap boards be sure
to resolder all the IC's.
Another thing that can go is the voltage that run the IC's.
IIRC they use apx -15 & +15 volts. If an IC shorts it
will either open a resistor or a little choke coil. More on that
if needed...............
73 Zeno
