AFG 1.0 AT Motor intermittently slows down with no load

Thread Starter


Joined Jan 18, 2022
I have an AFG 1.0 AT treadmill that randomly slows down, even without load. On cold startup (off for over an hour) after pushing start, the motor slowly starts moving, jittering, and making some weird noises, and eventually reaches a steady state speed. Some times it will work fine for 5-10 minutes, and there's a loss of motor power (Everything else stays on), the same sounds happen, it jitters a bit, and starts working again.

A couple notes, the noises doesn't happen when I turn the drive train by hand, and disconnecting the drive belt, still results in the jittering and noise.

the part numbers for the control board and motor are:
Motor Control Board Johnson Fitness JDYF02L REVg
Motor: Johnson JM01-013 2.25 HP

As far as I could tell the motor brushes looked fine, and there did not appear to be any exploded, or domed capacitors on the drive board.

When I was checking the input voltage to the motor during the jittering, it would fluctuate about 10Vdc (between 70 to 60 Vdc).

My first thoughts are to change the capacitators anyways, but I don't know if it could be anything else.

I haven't been able to find any similar issue regarding motors the suddenly slow down--all are with load (people stepping on treadmills).

Any help would be greatly appreciated.