I've got a question or two. When you removed the circuit board,did you do it by unsolder the 6 pins going to the connector? I just had mine out thanks to note about the To-220 mounting to the case, all this time I thought the nylon fastner was an adjusting pot! DuH! Anyhow it sure is fun getting those 6 pins cleaned, algined and resoldered and continuity and NO shorts between each other WHEW!1 that's a bear while IMRC on the motor still. I did feel like destroying the connector or the bond it has to the case.
All my parts tested good far as the basic Ohm meter tests. I did apply new heat sink compound, that transistor is isolated from the case. I never like heatsinking when you have to do that. I did notice two of the upper connect pins (pins closest to board edge) the solder was cracked.
For now I used nylon spacers, that had been isolation washers on an old toilet seat, to act heat break the steel bolts won't conduct heat quit as fast.
I'll see how it goes.
Thanks again Glenn?
Are you involved with electronics Glenn?
Paul
N8BUU