A4983 w/ Regulator pin not making contact


I have 4 of the A4983’s with voltage regulators (item# 1202) for use in a RepRap project but one of them only moves in one direction. I have the drivers wired to an Arduino Mega. The other 3 boards work fine in the circuit. When I change the direction pin for the problem board, I am able to measure 0 or 5V at the header but the motor still spins in one direction regardless of the DIR input.

I have had to unsolder and re-solder the headers a few times and I think somewhere along the way I lost the metal contact point for the DIR input so now the signal is not reaching the board. Is there a way to measure the DIR signal on the board itself instead of the headers? If it turns out the contact point is gone is there a way to put a new one on? or connect the input the board another way?

I appreciate any help on this! Thanks.



The A4983 datasheet (linked from the resources tab of the product page) shows the A4983 pinout, so you should be able to figure out which IC pin is the DIR pin. Can you use your multimeter to check for continuity between this pin and the appropriate header pin (with the board unpowered to avoid problems that might occur from shorting multiple IC pins together with your probe)? Your rework definitely could have caused a connection to come loose, though you might be able to work around it. For example, you could try to scratch off some of the solder mask from where the DIR pin trace leaves the header pin and create a solder bridge from this exposed copper trace to the header pin.

- Ben

Thanks so much Ben! I managed to scrape off some of the insulation and solder a little piece of copper strand to the exposed copper. Took a few hours to get it right but the board is back to both directions!

I’m very happy to hear you were able to restore your board to full functionality! Thanks for letting us know how things turned out.

- Ben