motor failure

We have the andy mark transmission and we got the ones to run the big cim motors and the small ones. We wired everything up and found the two bigger ones were not working but then we got them working by switching out the speed controller on one and the pwm on the other. we walked away for a couple minutes and now it doesnt work again. Nothing got moved and nothing is unplugged but now three out of four motors are not working. Has anyone ever had a problem simialar to this one.

I know the pwm cables like to randomly unseat themselfes causeing a bad connection. Last year we solved this by hot glue. the PWm cables is where I would start.

It is difficult to get the PWM cables to seat properly. When fully inserted, the brown shell should be exposed by no more than 1/8". Any more than that and the pins are not fully inserted. Otherwise invoke the Notke rule and go where the last person was working. All will become clear.

generally in engineering you look for a single point of failure. If three motors have stopped working then most likely one thing has failed that can stop all three motors

I would look at stuff like your ground connections (ground stud or the terminal block)

or make sure your SW guys didnt decide to test new SW when you were not there.

It very rare for two things to fail at the same time. Extreemly rare for three things to fail all at once.

Look for the single link that ties them all together.

A good example of this is when our programer decided to load so code to try out. I was called in saying that we lost the right drive train. After a few minutes of searching, I asked the programer to double check the code. Sure enough there it was. It is unsual for two of the same things to break at the same time.

Thank guys it was the pwms were not getting good connection i appreciate the help and advice.