I’ve got a few easydrivers that seem to refuse to drive my stepper, regardless of the setting of the pot. The chip stays cool and the motor just vibrates a bit if I drive the step input. I’ve checked the voltage on the vref pin and it’s good (5v). I have a known-good easydriver that works fine when I swap it in, so the connections and signals are correct.
This even happens on one that I let the smoke out of and replaced the A3967 on.
So, any ideas for what to test? Or are these drivers blown and I need to buy a new set?
I’m sorry to hear about your problems with the EasyDriver.
What I don’t understand is if you replaced the driver chips and the problems still persist, then the problem couldn’t be with the driver chip, right?
But unless the voltage regulator failed (which it didn’t since you have a good 5V) there really isn’t anything else on the board itself that I would suspect of failure. Circuit board traces? Resistors? I’d be very surprised if they failed.
Could your soldering of the replacement chips possibly be suspect?
I have heard (rarely) of others who have experienced symptoms similar to yours - in some cases we never figured out what went wrong, in others it was because of intermittent connections (either power/ground or to the motor). Higher supply voltages apparently make these problems more likely. For example, I was able to power an EasyDriver with 24V, and by plugging and unplugging the motor about 50 times as it was running, I got the driver chip to completely fail. At 12V, I was unable to get the same problem to occur even after hundreds of connection/disconnect cycles.
So I don’t have any good answers for you I’m afraid.
I am running the driver at 24v, but I’ve never disconnected the motor without removing power first. I’m definitely not precious about my soldering skill, so a poor joint or three aren’t an impossibility; I’ll give them another going over. I did compare the voltages on all the pins with the ones from my good board; everything seemed the same except for the motor outputs (A and /A almost identical, same for B and /B).
I’ll give myself a few days of mucking about to see if I can get them to work, then I’ll just chalk them up to experience and buy some more.
