Bad EXP sensor ports

I am teaching my students about the various types of sensors which can be used on the EXP robots. I passed out the version 4 bumper sensors to 15 different groups today. On one robot, none of the V4 sensor ports detect any signal from the bumper sensor I gave them. I gave them a different sensor. We had the same results. These two sensors worked just fine on another robot, so I know it is a port issue. Has anyone else experienced this? The brain is still under warranty, so I know I should be able to get it replaced. I am guessing there isn’t a ‘reset’ switch somewhere either??



Did the 3wire device show up in the devices screen ? and the bumper was not working when the 3wire port was selected and set to digital input using devices screen ?


Same issue. 7 EXP kits. One brain doesn’t respond to known-good bumper switches on any of the A-H ports. Any other path to resolution other than a warranty return?

Also, when I try to do a factory reset, the programs stored in slots and the brain name remain. Shouldn’t a factory reset reset those? I’m concerned I’m not doing it right but can’t find any info beyond selecting factory reset in the brain menus.

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I also have a robot here that doesn’t respond in any of the 3-wire ports

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contact vex customer support.


I am using the same EXP brains as last year at this time and the bumper sensor is not showing up as a 3 wire device on the devices screen.

A bumper sensor will not show as an individual device in the devices screen (and never has). You should see the three wire port, select that and then configure the input as a digital input to test a switch.



It does not even show up as a three wire device.

As before, give VEX support a call and they can help you troubleshoot. It sounds like the 3wire port controller either is damaged or needs its firmware reloading.