Hi all. I attached a schematic and service manual descriptions of a motor speed control circuit for a Leslie model 60s organ/piano speaker. The motor doesn't work so I am asking for help. The service manual says to check transistors Q29 or Q30, or transformer T4 if the motor doesn't work. I checked all those and they seem OK.
As far back in the circuit I can trace is to the input primary of T4. There is no AC voltage happening here, and so I believe it is something a bit earlier in the circuit. I don't really understand the circuit too well. I think the motor is an AC motor because it says 24V 60HZ. So evidently there should be some kind of AC current supplied to the motor, but there is no AC or DC voltage going to the motor. I don't have an oscilloscope so I can't see what's happening anywhere except with the fluke multimeter.
Should I take out the circuit board and check all the components? Can I check all those with the multimeter? I don't know what the function of the IC unit there is, but it looks like it generates some kind of square wave or something. This is a circuit from the mid 1970's I think.
Thanks for looking and thanks in advance for any help or suggestions.
As far back in the circuit I can trace is to the input primary of T4. There is no AC voltage happening here, and so I believe it is something a bit earlier in the circuit. I don't really understand the circuit too well. I think the motor is an AC motor because it says 24V 60HZ. So evidently there should be some kind of AC current supplied to the motor, but there is no AC or DC voltage going to the motor. I don't have an oscilloscope so I can't see what's happening anywhere except with the fluke multimeter.
Should I take out the circuit board and check all the components? Can I check all those with the multimeter? I don't know what the function of the IC unit there is, but it looks like it generates some kind of square wave or something. This is a circuit from the mid 1970's I think.
Thanks for looking and thanks in advance for any help or suggestions.