A4988 keeps frying

I recently ordered two #2981 A4988 Stepper Motor Driver Carrier, Black Edition (Header Pins Soldered) to run a Minnebea hybrid stepper motor (17PM-K442B) minebea.pdf (592.4 KB)

I made the connections as guided by the a4988 sheet.

I had limited my supply Voltage to 24V and current to 1A.
I was able to run the code I found online to test if it works, It did work but for a few seconds and things stopped.

/*     Simple Stepper Motor Control Exaple Code
// defines pins numbers
const int stepPin = 3; 
const int dirPin = 4; 
void setup() {
  // Sets the two pins as Outputs
void loop() {
  digitalWrite(dirPin,HIGH); // Enables the motor to move in a particular direction
  // Makes 200 pulses for making one full cycle rotation
  for(int x = 0; x < 200; x++) {
  delay(1000); // One second delay
  digitalWrite(dirPin,LOW); //Changes the rotations direction
  // Makes 400 pulses for making two full cycle rotation
  for(int x = 0; x < 400; x++) {

After connecting the other A4988 I knew it was fried.
I limited my current to 0.7A as the motor was consuming that much. So I limited my supply to 0.75A on the converter. I was able to run to run the motor for couple of times for a minute but again it stopped working.
I am not sure what is wrong.

Breadboard contacts are not designed for high currents, and should not be expected to carry more than 100 mA or so. One possibility is that the contacts burned, leading to intermittent motor connections, which can instantly destroy a motor driver.

Connections to the motor power supply and the motor should be made with suitable wire sizes and soldered directly to the motor driver.

The data sheet you linked covers several motors, designated as UNIPOLAR. Which motor do you have, and exactly how have you wired it? Please post a hand drawn wiring diagram, with the leads carefully identified.

Motor&Circuit.docx (485.2 KB)
Please the document attached which has the info on the motor and connections.

Please post an image file. Many people, including me, won’t open unknown .docx files.

Sure, Here you go!


So when running the program to drive the motor with one of the a4988 drivers, the power supply reading changes to 5V and 1A from 24V and 1A(originally supplied).

Thanks for posting the clear drawing, which looks OK.

I strongly suspect burned breadboard contacts and recommend that you carefully solder all connections to the motor driver.

A single intermittent contact to a motor coil can generate a high voltage pulse that will incinerate motor drivers.