sanyo m7900k motor adjust speed

[aus10whales]

hello all,

i recently repaired a sanyo m7900k boombox. new belts, idlers, general cleaning, etc. it’s all working perfectly now but the motor runs very slow. if i sync up a tape with a digital file, it starts going off track after a few seconds.

the issue is, per the service manual, “The speed can not be adjusted by means of motor in this machine.”

there is no variable resistor built into the motor, and when looking at the board that the motor is connected to for power, i cannot find anything there either.

is there really no way to adjust the speed on this thing? the slowness has made it basically unusable with cassettes.

any help and guidance is much appreciated!

thanks

 

[Daz 125]

there should be a speed adjustment pot on the motor..look at the back of the motor and u will see a hole..put in a small flat ended screw driver and gently turn clockwise. it should speed up. if not then turn it anti clockwise ..just go easy with it..u dont want to break the speed pot

 

[aus10whales]

there should be a speed adjustment pot on the motor..look at the back of the motor and u will see a hole..put in a small flat ended screw driver and gently turn clockwise. it should speed up. if not then turn it anti clockwise ..just go easy with it..u dont want to break the speed pot

hi, thanks for the response. usually that is the case and i have done that many times, but not for this boombox. the casing on the back of the motor is solid. i even removed the rear casing plate of the motor to see inside and it’s just the motor, no circuit board with a pot. the small board that the motor is connected to does not have a pot to adjust the speed either. unfortunately this is why i’m lost.