Is my jrk 21v3 toast?

After working great since February I think my jrk may have gone kaput. It gets very hot when I attach motor power (24V). It no longer communicates over USB. The USB led is off. Error LED is solid red. Output status LED is solid yellow.

Amp draw in normally less than 1A but I haven’t checked it lately.

I’d like to know what happened to the jrk so that I can avoid damaging the next one.

As long as max recommended voltage is not exceeded what can kill a jrk? Will shorting the motor wires kill it? How about if the power supply wires get connected to the motor terminals or some some other combination on the screw terminal strip? Reverse polarity maybe? None of these things happened, I just wonder what can kill the jrk. I seem to recall that it has self protection circuity.

I don’t see any discoloration on the board or any other sign of overheating or physical damage. I hope I look that good when I’m dead.

Is there anything I should try before declaring my jrk dead?


Here’s some additional information.

One chip on the jrk gets hot even when the jrk is only connected to the host computer’s USB cable (motor power supply not connected). I believe it’s the PIC microcontroller chip that gets hot. But why? It doesn’t handle much power, does it?

thanks again!


I am sorry you are having problems with your jrk motor controller. The jrk has many protection features including reverse voltage protection, but there are still lot of ways you could connect things wrong and damage it. You can see more about the protections the jrk controller has on the jrk’s product page.

Did anything in your setup change before it the jrk stopped working? Can you post a picture that indicates which chip is getting hot? You could use a picture from our website like this one. What motor were you controlling with the jrk? Are you referring to the motors when you say: