Interesting Vexpro Victor 888 failure.

[billbo911]

This past season we purchased 4 Vexpro Victor 888s during build season. They all worked flawlessly up until CalGames. At some point, at least one of them failed, but in a peculiar way.

When the joystick is in the middle position, there is no output from the Victor, as would be expected. Then once you move the stick forward to about 10%, the Victor outputs to the motor approx. 10v. As you continue to advance the stick, the voltage to the motor increases fairly linearly until full power is achieved.
When the joystick is pulled in the reverse direction, the Victor continues to output 0v to the motor and there is a clicking sound from the Victor and the status LED on it blinks in sync with the sound. The frequency of the clicks is about 3 Hz.

We thought that the calibration of the Victor might have somehow become corrupted, so we recalibrated it. There was no change in the behavior of the Victor after calibration.

Disassembling the Victor showed no signs of component failure. There was no burnt smell at all. We found no debris inside that might be shorting anything out either. We don't believe any of the FETs are shorted, otherwise the motor would be receiving power at all times. It sounds more like the FET drive controller is toasted.

Has anyone else ever seen behavior like this?


PS, If Vexpro would like this one back to diagnose it, just ask.