Preselector sometimes press the normal press, sometimes not receive program, after a primary switch is poor contact, 2 it is preselector potentiometer poor contact. If the primary device has this phenomenon, if there is a fault should consider an AFC circuit. 2QFservice manual download site
 2QFservice manual download site
 2QFservice manual download site
The machine after eight preselector has press the phenomenon of show. But to put an AFC switch OFF, still have this phenomenon. That is not an AFC circuit malfunction. 2QFservice manual download site
Check the keys filters switch, no contact undesirable phenomenon. The multimeter measuring preselector potentiometer, found the primary potentiometer resistance movements are very big. 2QFservice manual download site
Carefully remove the potentiometer, resistance wear not heavy, but spring of elastic are small and so poor contact. Each spring pull up some, restore elasticity, washed all the resistors. Installed machine back to normal again.2QFservice manual download site