A4988 chip blown

Hi I have now blown up (I assume) connecting logic supply +5v and gnd +24v for motor but motor not connected all signals log ok I.e reset high enable low and sleep high. Driving step and direction via a pic But after I scope signals the A4988 stops outputting and all pins are pulled low, the pic signals reset and sleep now limited to about 0.7v
I have changed the A4988 chip twice with same results, don’t want to keep repeating this cannot see what I may be doing wrong.

Can anyone help pls


I am sorry you are having problems with your stepper motor driver. Your description is very difficult to follow (e.g. are you using one of our carrier boards, or are you actually talking about the A4988 IC by itself?). Is there something other than your inability to get it to work that makes you think the driver is damaged? Can you post a diagram of how everything is connected and some pictures of your setup?

Are you saying that things were working as expected until you tried to look at the signals on your oscilloscope, at which point the driver stopped working? Can you try to more clearly describe the situation?


Hi I am using one of your modules and simply connecting power as per your data sheet with 10k pullup resistor on reset pin, using a dual channel bench top PSU with no motor connected

The driver does not work at all the reason I am using scope is the board is not working and discovered that even though I have pull-up on the reset pin it is only at 0.7V also the pic lines for the step and direction are only going to 0.7V

It sounds like you might have damaged the board with an LC voltage spike. Did you install the capacitor between VMOT and GND as the warning note under the “power connections” section of the A4988 product page suggests? Can you post some pictures of your setup?