Port 10 only allows a motor to spin in one direction

Problem: Any motor plugged into port 10 in our cortex will only work going in a single direction.

Analysis: We have tested multiple motors in the port and they all do the same thing (turn in one direction) and we have replaced all the wiring connected to that port. We have also flipped the motor controller wire to the motor wire and the motor turned in the opposite direction from before but still will not work in the other direction. Then we tested just that port with a dummy program to spin in both directions but it still will not work properly even though the debug window shows that it’s outputting 127.

Conclusion: The motors are not bad, non of the wiring is bad, and nothing is wrong with the program. It was working before and randomly started doing this while driving with the same program on we’ve had for awhile. We think there is the possibility that the program is somehow causing the port to short circuit or break in some way but we’ve checked the program and it’s simple as can be. This has happened two other times (first time port 1 and then port 10 and now port 10 again). After two months it has happened once again and we don’t know what’s causing it or how we can fix it.

Our fix: We are replacing the cortex (it’s proved that the motor works in port 1 and 10 properly) but we would still like to know what cause this and if it’s possible to fix.

I’ve found one other post relating to this but it did not have much help on it so I decided to to post a newer one (old post is two years old) and if anyone can point me in the right direction with either a post I skipped or if they can help with their own knowledge that’d be great.

I’m sure someone else can offer more insight into this, but it sounds like there is something wrong with half of the H bridge circuit that powers port 10. So the easiest solution is to either avoid ports 1 and 10 and only use motor controllers, or replace the cortex like you are doing.

Same issue as this thread, damaged MOSFET in the H-bridge