3MP1 Pin Board 1. f (filament) 2. G 3. F 4. Y1 5. Y2 6. no connection 7. X1 8. X2 9. A 10. nc 11. K 12. f (filament) Voltage test: f to f (filaments or heaters) = about 4-6VAC Other voltages referenced to ground, 0VDC (tab of 7805) Pin # voltage 2 -300 3 -150 4,5,7,8,9 about +250 11 -295