Computer Damage

Has anyone experienced any type of hardware damage to a computer when using VEX hardware?

We have 12 Vex Super Bundle kits and have lost 4 motherboards on their host computers. The computer do not boot or even post to the BIOS. We have been slowly tracking down and ruling out any other hardware or other peripherals. The only common thing across all four of these computers is the Vex kit and with that the included USB to serial cable.

Any help or suggestions would be great. At this point we have put the class on hold for fear of losing another computer.

I have never heard of such damage being caused by the Vex programming cable, and I’d be very surprised if this was the cause of your problems. The USB-to-serial cable is just a generic Prolific serial adapter; it isn’t really a custom Vex design. Lots of identical Prolific adapters are in use around the world for a large variety of purposes. If they were causing problems, there would be a lot of computers dying from it.

In the past when I’ve seen lots of proximate computer failures, it is usually due to something common to the space the computers are in (poor wiring, lots of static electricity, poor climate control, vibration, and in one case a saboteur).

Best of luck tracking down the root cause,

  • Dean

I have been using the Vex Programming Kit for over 3 years as well as being a member of this Forum for that entire time, and have never experienced or heard of this issue.

You have ALWAYS used the Vex Programmer with the USB-to-Serial adapter on each computer?? Never used the Vex Programmer directly with the effected Computer??

Did the Computers let you program the Vex Controller, before making the Computer Inoperative??
OR did the Vex Programmers “lock up” the Computer when attached, and then when you reboot, the Computer is Inoperative??

It is possible, but not probable that something could have damaged the USB-to-Serial Adapter, that could cause the USB port on the Computer to be damaged, that could cause the Computer to not POST. But that is a lot of “could’s”…

To the best of my knologe, both RS-232 and USB ports use a Short Circut protection, like the one mentioned in, Implementation Strategies for USB Circuit Protection Technology

If all the computers are the same make and model it may just be bad parts.

That is correct. We have always used the orange usb-to-serial cable that came with the kit. Never a direct connection.

We have been using the computers to program the controllers for over 3 weeks now without issue. Sometimes we would get a computer that froze and had to be restarted, but it would restart.

They are all HP d530 SFF computers. I would have thought it was coincidence, but I feel like that is stretching it for the exact same issue on the exact same type of computers, doing the exact same thing. Seems almost too much of a coincidence, but I’m not ruling that out as a possibility.

I appreciate the help everyone. I am not bashing the product or anything like that, just trying to track down a cause.

So the USB-to-Serial Adapter has always been part of the Programming Processes.

So how did the First Failure Occur?? What did you try next??

Did you move the USB-to-Serial Adapter and Vex Programmer from Machine to Machine after the First One Failed to Program, or After it Failed to Boot, and see if it would program, or did ALL of them Fail to Boot.

Was the USB-to-Serial Adapter and Vex Programmer plugged in at the Time of Boot, or did you try to Boot without them??

Once computer 1 failed we moved to computer 2 working with the same kit (cable, controller, ect). Eventually computer two then failed. A little less then a week later. At this time computer 3 then failed and the hardware used on it was moved to computer 4 which then failed.

It was at this point we started to see a trend and started thinking something was up. The Vex hardware has been moved to test boxes now to try and rule out this usb-to-serial cable could be bad over this cable. Process of elimination. So far, no progress has been made in that department as its all still working on the test box.

We have done it both ways.

That is correct.

In a previous life I worked for a company that designed and installed large local area networks and the various components and wiring to make it work. Mass die-offs of PCs are not unheard of and it is wildly unlikely that a device attached to the USB port would bring down an entire PC. Some things to think about:

  • Is your power dirty? Are these computers plugged into UPS devices? Is the voltage out of band for the PCs? Power problems cause a lot more PC problems than most people think.

  • If the PCs are all identical models purchased at the same time, it’s more likely, as someone else said, that they share some component that is failing at about the same time. I just did a quick Google and there are quite a number of cases of failed power supplies for this model. Are you sure it’s a motherboard failure and not power supply?

  • This is another power supply theory – do those computers have tiny, marginal power supplies? I wouldn’t expect it, but it’s possible that powering a rarely-used USB port might cause just enough power drain to take out a marginal power supply.

  • I see them on the Web at used-computer stores for $200-500. Are these old computers? Obviously, the serial port doesn’t use much power, but it could stress an old machine that was marginal already.

For what it’s worth, in four years of running a VEX competition program and talking to other VEX users, this is a problem that I’ve never heard of before. Good luck.

I just destroyed a motherboard with a flashdrive so the vex hardware doing this could be possible imo.

I left a drive in and the pc booted from the flashdrive which for some very odd reason started booting free dos so I unplugged the drive and rebooted (big mistake turn off, unplug, then reboot). For some odd reason when I unplugged that drive it fried the bios and the integrated gpu why I don’t know but again a flashdrive did this.

So if for some reason the computer bios tried to do something with the usb to serial chip upon bootup and something interrupted it I can see something like the above happening.

I’m no expert in this but its possible especially if the bios is buggy for it to become corrupted.

Our First Tech Challenge team experienced three mothboard failures last year while using USB cables to NXT controllers. I was not intimately involved but I believe they were all the same make and model computers.

Our conclusion was that the USB ports did not have adequate ESD protection and discharges to the attached robot were being routed directly into the motherboard. A similar problem occured with the FRC drivers stations and Ethernet ports. Discharges to robots while they were tethered to the drivers station destroyed either the ethernet hardware or the entire computer.

I would suggest trying a USB hub powered from a seperate power supply to try to isolate the programming cable from the computer. If the hub could be grounded it would be even better.

In the case of the drivers stations mentioned above, the problem was totally eliminated by using a cheap ethernet hub between them and the robot.

You could build a custom device to protect it with opto isolators which would completely isolate the circuit with no electrical connection between the computer and programmer. An opto isolator is a chip with an led at one side, empty space in the middle, and some sort of detector on the other side that turns on or off if there is light. I have a few of these that have a darlington pair built into them which is perfect for isolating devices and running them up to 100ma.

So if something substantial happens the isolator chip will fry out and stop whatever it was from reaching the circuitry on the other side (computer) and at like a dollar for a 4 channel isolator it wouldn’t break the bank.


We have been speaking with Innovation First the makers of the orange cables used to connect the controller to the computers. They are going to replace all of our cables and we will see where that leaves us. Thanks for the help everyone.

Welcome to the VEX forums, and a huge congrats on the Championship WF.

We learned this as well in our FRC robot last year. Static discharge damaged our CRio.

So far, we have not had any bad experiences with the VEX equipment. Maybe IFI shields their stuff better than NI. :rolleyes: