V5 brain ports break continually

@jpearman The cortex was running 1.02 at the time, didn’t spot the update before the comp.
Edit: We have now updated, port 2 & 7 of the cortex cause a red flashing light on motors, no matter the motor or cable, those motors work on other ports. We do have one motor that gives no light and no connection on any cortex cable etc…

@KMonkeys Yes there was some static on the field, but I thought the V5 system was a bit better insulated and this should be less of a problem than it was with V4?

We had the same issue which seamed related to two locations on the robot and we lost 5 ports on the V5 brain. It’s being replaced under warranty.

One seemed related to a 900mm VEX cable.
One seemed related to a 6’ self-made wire.

Both wires were tested for continuity on the four wires and no shorts.

The robot also had another 6’ self-made wire in another location that was never related to any problems.

The problems didn’t crop up until the team started putting in a lot of practice time before and at their first competition.


@MikeHS Thanks, I’ll check the cables. All ours are pre-made. One was on a1500m the other on a 600mm. It does seem a bit strange to me that this could be a wire fault.
This all happened mid regional event for us, so not great timing.

I’ve contacted VEX about it to see their take on the issues.

I have no idea what the fault is. Just providing whatever info I can. Our motor port failures were isolated to two locations on the robot, but we swapped one wire and motor (when the first port failed, the corresponding motor also failed at the exact same time). After the tournament, I checked all three wires used and all were fine (no broken connections and no shorts between the wires).


We’ve just uploaded a new article to the VEX Knowledge Base that details our recommended safeguards to minimize Electrostatic Discharge and possible component damage. It can be found here: https://help.vex.com/article/148-vrc-team-esd-notice

We also recommend that teams watch this video for tips on covering their fields with staticide:

I’ve blown 4 ports in the past week. I’m using the assorted sizes of wires from Vex.

@DRow Does this mean that ports breaking is related to ESD?

My post was more of just a general update. There had been a few posts above saying that it could be caused by ESD, my post was just trying to show the best way to avoid that happening.

Due respect to the product and to you, that spray makes the field significantly stickier, which affects game play a ton. Teams had to reprogram their autonomous modes and add new guards to their robot literally while they were at worlds because game objects moved so differently on the high friction fields.

It also can apparently cause cancer and reproductive harm. And with 36 tiles and 10 sprays of spray per tile, you are covering your field with 360 sprays of potentially dangerous chemicals.

EDIT: the product does not actually cause cancer or reproductive harm- I was looking at the wrong product’s warnings.

If the issue really is just static, spraying some water onto the field every hour should do the trick. It’s a little annoying, but a tiny bit of dampness isn’t going to affect how the objects move on the field nearly as much :slight_smile:

For the record, our new recommended spray does not contain any carcinogens, and received a 1 out of 4 for its NFPA Hazard rating.

Source, the MSDS Sheet: https://media.digikey.com/pdf/MSDS/ACL%20Staticide/2002,%202005.pdf

Don’t let that get in the way of a sensationalist rant though.

This is an excellent point :slight_smile: I was looking at the wrong product , sorry about that!

Lol and EPs wonder why their reputations suck on the forums…

The problem is prop 65, everything in California causes cancer.

I’m not really sure that’s relevant. I rarely ever post but it was a very strong claim that should have been called out. I don’t know that my support for educational robotics has any bearing on that. I wish I could organise more events but the few I do plus the support I give numerous teams worldwide is the most I can do. It’s sad that you think VEX EPs are out to get you. I for sure am not. I agree with a lot of the recent criticism of VEX, there are numerous issues that need to be sorted but creating an unnecessary fear culture around something that could help teams at tournaments makes no sense.
Do I think the V5 roll out has gone well? No. Do I find the recent advice from VEX a surprise? No. Do I know why V5 is currently unavailable? No. Do I think that V5 as it stands is better than Cortex? No.
Do I even dare think that BO1 is better than BO3? Absolutely not. Do I still think it’s worth supporting the program? Yep. All. Day. Long.

I know the sign has gotten a lot of attention but it seems like there is actually some legitimacy to it. A lot of commonly touched statues etc at Disneyland apparently have unsafe levels of lead.

Anyhow, this doesn’t really matter, I was looking at the wrong product and the antistatic that Vex recommended does not, in fact, cause cancer. And for the most part I totally agree that Prop 65 is silly :slight_smile:

Nice sensationalist rant :slight_smile:

If you want to continue this lovely conversation, why don’t you DM me so this thread doesn’t get derailed any further.

This is an update on the V5 Brain port issue. One of the team that had seven of their ports died on them within two competitions had a new Brain replaced. The new Brain were upgraded to latest firmware (v1.03). Regarding DRow’s post about using anti static on the wheels, the team did put on anti static on all four wheels on their robot for today’s competition. Granted that they didn’t use the exact same anti static that VEX recommended (Heavy Duty Staticide product) but they did apply anti static spray on their robot wheels before the competition.

Anyway, today’s competition, they had one port that was connected to the lift (about two feet long wire) died on them. However, this port isn’t completely dead like the other seven ports that died on them earlier that was on different Brain. This new half dead port still recognizes the motor being plugged in but it doesn’t generate enough power to move the motor. The red light on the motor port connector kept on blinking red instead of solid red.

I have ordered Heavy Duty Staticide product and should be here by Friday. I will have the kids apply the Staticide onto all their robot wheels for next week’s competition. I will update the results after next week’s competition.

Good to hear your update. Just wondering, however, are you applying the Anti-static spray product to the wheels on the robot itself, because you are not permitted to spray it on the competition tiles? Also will it work with all the standard VEX wheels, or is there a particular procedure for each of the wheels?

The kids spray the anti static onto the wheels on the robot itself because there is no guarantee that the EP spay any antic static onto the field. They have informed me that certain competitions have more static than others. So to be safe, the kids are trying to avoid having dead port issues, especially during the competition.


A team in my region was having some issues with static in SS, so they attached a cut and frayed extension wire to their chassis, and they grounded the other end. I have no idea if that is legal or effective, but they were convinced it was both. Maybe some combination of these two techniques would work the best?

@DRow cannot say that static is killing the ports on the V5 brains.

First, I think, they are not 100% sure what is the exact mechanism. There is always some level of static in the air this time of the year, but ports are not all dying as soon as you put the robot out on the field - there is something else that is triggering ESD events. It could be wheels or flywheels generating extra charge as they move, it could be long wires accumulating surface charge, or it could be intermittent connectivity in the ports, …

It would have been nice if V5 brains had dedicated ESD protection circuitry, but they don’t and without knowledge how exactly ports are killed it is not clear what we could do to protect them.

The second reason is that once you admit that V5 brains are inadequately protected from ESD, then the next logical question would be: what about recall? And that is hardly possible, because you either need to issue the fix (which may be too long to produce, too costly, or both) or you need to reverse V5 transaction, which is difficult, because you could refund the money but reuniting teams with cortex hardware is hard.

For example, one way to protect the ports, without redesigning V5 brains, would be to insert surge protector between V5 ports and motors. Each having TVS devices and redundant ground connections to V5 brain ground. That would take time to design and manufacture and will add to the costs.

If that is the case, issuing anti-static recommendation to teams and EPs is perfectly reasonable thing to do, because it could be implemented quickly and doesn’t tie up any additional VEX resources. It has a potential to save the season for any team that got static vulnerable V5 brain on their hands.

Before VEX issued this recommendation I was researching a way to protect V5 from the team’s side. Making your own TVS protector is both not VRC legal and would be beyond the skill set of an average team.

If static charge accumulation on the fields is reduced by the spray and TVS port protection is not possible, then the next best line of defense might be to shield the wires and tie electrical ground of the V5 brain to all metal subsystems of the robot. Protecting wires is legal.

I found several products that might be able to achieve such task:

Flexo Anti-Stat
Flexo Conductive Braided Sleeving
Flexo® Chrome Expandable Braided Sleeving

Assuming average V5 robot needs about 16" of cables, then it will cost $20-$30 to protect it, depending on the supplier.

My questions to the mentors who has experience protecting electronics from ESD are:

Do you think this will work? Do you think it is a good idea to invest into one of these products as an insurance policy to protect V5 brains?

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