V5 port burnout

it is tucked well-inside the chassis - I would suspect about 2". Has steel on 5 sides - almost like a Faraday cage.

I know this doesn’t prevent the cables from picking up static but honestly these ports died when there wasn’t much movement. Plus being in the south the humidity is still pretty high and seldom experience ‘winter-induced’ static - esp this early in the season

1 Like

Thanks - we suspected this was like the Cortex and did this - I have to look closely but it looks like individual ports are dying

FWIW - we only have 5 motors

It is about three - four inches

I have 8 ports burned out in our V5 and it sucks because we want to get a replacement, but we don’t have hope that we will be able to get it before the competition is over.

I’m sorry about that last year we had to use V4 for one of our teams. Good luck with an replacement.

wow - 8 ports!?! Guess i can’t complain!

maybe you can coordinate w/VEX Tech support over the Christmas Break!

They seem very responsive

So ‘static’ or shorted cables are the only known culprits?

Had ports short out multiple times, oddly only kept happening to the same intake motor. Knew it wasn’t the programming considering the 2 intake motors were programmed the same way. Initially tried changing the port with new cables. After the 3rd time we replaced the motor and haven’t had issues since.

1 Like

VEX Tech Support is very hesitant to acknowledge static as a cause of damaged ports and motors. While you should definitely contact them, be careful of this.

So far this season, I’ve lost 8 ports and 3 motors. During this time, I’ve done quite a few experiments and research with the brain.

  • Ground your brain to the robot. On the bottom of the brain, there are brass screw holes. Make sure metal is screwed into those. My team has steel 1-bar attached from there to the drive, and from what we can tell, eliminated our static issues.
  • Use anti-static spray on your fields, and make sure the competitions you go to do as well.
  • Use anti-static wipes, anti-static spray, or drier sheets on your wheels.
  • Use standard vex cables whenever possible.
  • Make sure all custom length cables are crimped properly. The black rubber should be partially inside the connector.
  • Make sure there are no internal or external damage to the cable. A wire tested helps with this.
  • Keep cables as short as you can. Longer cables pick up static easier.
  • Be mindful of sources of static in the room.

There are other things that can be done, but these are the main ones.


I’ve seen a few mentions of static frying the ports. That is likely a key role on why they burnout. I know I’ve static shocked a few of my V5 ports now.

I’ve seen this rumor a couple of times now. There are 4 connectors, each with five ports, but other than that all ports are equal and do not share anything. You do not need to spread out motors in the way we had to with the cortex to balance power or anything.


Nice check list - thanks!

Has VEX confirmed the brass inserts are really a ground? I suspect this is part of the plastic mold - unless the PCB also attaches here…

If not maybe we can figure which pin on motor-connection is ground and use it…

We had an issue with “RotateFor” not stopping if we used port 11. We switched it over to port 12 and it worked as intended.

Wait are you telling me that you don’t use those for attaching the brain?

This is great - very impressed w/the design.

However, wouldn’t empty ports give room for heat to escape?

One Q that came up was grounding the Brain - someone suggested the brass inserts were also ground - can you pls confirm?


They are not connected to ground.


Thanks - would it be reasonable to use the ground pin from an un-used motor port to ground the Brain then?

see this Q&A



I didn’t think it would be connected to the ground for the brain, it just seems to take static away from the brain. Is that possible? Or is it something else that seemed to solve our current static issues?

It is perfectly legal to use conductive sleeve/braid as the wire protection per <R7f>.

Such wire sleeve will let you electrically connect all parts of the robot and will help prevent static electricity built-up between them.

Once again, it is perfectly legal per <R7f> (See the Game Manual).

I understand that GDC ruled consistently with <R21> of “no modifications to electronic components”, but it is unfortunate that there is no detailed knowledge base article other that ESD Notice and it wasn’t linked from the Q&A.

A lot of teams are struggling with damaged hardware and VEX is mute on any hardware changes that could increase ESD protection.

Then if you really want to connect electrical V5 Brain ground to the robot chassis you can get creative with legacy wires and orange jumpers:

But you need to be very careful, because it could potentially create even more opportunities for ESD damage if metal subsystems of the robot are not electrically tied to the chassis first.


My school has had many ports blown out on Brains and on the motors themselves. Now with the Cortex we’re not sure what blows the port but it may be over running the port and the motor. What’s weird is with Motors we have encountered 2 issues, the port inside the motor has become loose and we get contact with a cable if we wiggle it. Or a port that’s completely bad all together. Which I wonder if there’s any similarities between a v4 motor blowing and a v5 motor blowing. I think part of the issue is v5 doesn’t have fuses so whats happening is that if the cortex or motor is overvolted we end up blowing the ports. The cable used for v5 is interesting too because the guage of the wire is smaller than CAT 6 cable. CAT 6 is rated for 5 Volts so does it also mean we’re pushing more power then the wires can handle?