I recently purchased a few Pololu A4988 driver carriers for my project from RobotShop.com.
However, the driver carrier was defective, and started sparking and died after 15 seconds of use. I contacted RobotShop, and they said before I am able to get a replacement, I must troubleshoot with Pololu via the forums, and get your permission for a replacement (as odd as that sounds), so here I am!
I am using a sanguinololu board, and I’m controlling Nema 17 stepper motors using these A4988s.
After soldering the 16 pins (8 on each side), I plugged the driver carrier into the proper socket on the sanguinololu board for testing and calibration (using the potentiometer), and brought the motor up to the same speed as the others (all controlled by their own A4988 carriers). After about 15-20 seconds of steady operation, the driver carrier started sparking and then died completely.
I took out the dead carrier, and replaced it with one of the other working A4988 carriers (just to test if it was the socket/sanguinololu board, or the pololu a4988 causing the problem), and all the other driver carriers worked fine with over 5 minutes of constant operation (in the same socket). I checked my solders under a magnifying glass, and confirmed with a beep test using a voltmeter, that there were no shorts. It was a defective board.
So where do we go from here? This project has a deadline coming up, and I need a replacement as soon as possible.