Motor issue!!! Help

Hello i am a member of team 2552 The PiThons and we have come across another weird problem. One of our motors is acting up. What it is doing is when plugged in with 5 other motors if it is plugged in on the same side as the other 5 motors the brain only recognizes 3 motors (but when a normal motor is plugged in it is fine) and second, when we remove that motor from the side with the 5 other motors and plug in on the opposite side of the brain it isn’t recognised. we don’t know if there is anything that we can do because we have swapped wires and brains and it always does the same thing. Thanks for any help. Also Here is a link to a vid about the motor issue that we took

  • The PiThons

Aloha Zach,
It looks like it could be a bad motor. Here is one technique that our team carried over from VEX. When determining motor port selection what we do is we separate our motors into two categories. LEFT Motors which are on the left of our robot and RIGHT Motors which are on the right side of our robot. Ports 1-6 are dedicated to the LEFT Motors and ports 7-8 are dedicated to the RIGHT Motors. On each side the 3 motors are spaced out evenly also. So for the LEFT Motors we will use ports 1, 3, 6 and for the RIGHT Motors we will use 7, 9, 12. Any sensors are plugged into ports 2, 4, 5, 8, 10, 11.

The logic, at least in VEX is that within the motor ports there are two internal breaker for the motor ports in the brain. 1-5 has a breaker and 6-10 has a breaker. So if we divide up the motors evenly between the upper half ports and the lower half ports then the internal breakers will not trip.

Although I have not seen any documentation validating that the VEX IQ Brain is constructed with the same internal breakers as the VEX Coretex we have opted to follow the same logic when wiring. Call it logical or call it superstition…it works for us. It may work for your team also.

Best of luck.


Yeah, no superstition ipanavigator. Stuff happens. Although sometimes it is motor, a sensor that is inline is suspect. A bad sensor incorrectly identifies as a bad motor error on brain while motor works fine. Try unplugging the sensors and see how many motors are shown in firmware updater tool.

Yup. Sensors can make these errors occur also. Good call.


Thank you for the info jpearman. That information is very useful.