4 Known Bad Victor 888s

[Robby Unruh]

Our team just wired up our prototype bot and much to our surprise, we have 4 bad Victor 888s right out of the box. We are positive that our wiring is correct- it was done by a 4th year member and double checked time and time again. We have 6 more we got with our shipment and are going to test them tonight to see if they are good.

We plan on returning them and/or getting new ones, but have any other teams had an issue like this where multiple motors just seem to go bad?

These are directly out of the box. We bought them before build season started from VEX Pro.

[Jon Stratis]

What behavior are you seeing from the "bad" victors? could it be a calibration issue?

[Robby Unruh]

Originally Posted by Jon Stratis

What behavior are you seeing from the "bad" victors? could it be a calibration issue?

When we try to calibrate the bad ones, they just continue blinking yellow. They don't flash red/green/yellow like the good ones do. At first we thought it might've been our CIM motor somehow blowing it up, but we swapped a Victor out with another and it worked fine.

We are using AM Super Shifters, and pushed the robot maybe a maximum of 8-12 inches on the ground on low gear last night when we tried to get it driving. Could this have blown the speed controllers?

edit: Swapped a bad one out with another, and we have liftoff. Sure would be nice to know how it broke. The manual says the problem is "internal damage"- which could be anything.

[Aren_Hill]

Originally Posted by Robby Unruh

When we try to calibrate the bad ones, they just continue blinking yellow. They don't flash red/green/yellow like the good ones do. At first we thought it might've been our CIM motor somehow blowing it up, but we swapped a Victor out with another and it worked fine.

We are using AM Super Shifters, and pushed the robot maybe a maximum of 8-12 inches on the ground on low gear last night when we tried to get it driving. Could this have blown the speed controllers?

If it just continues blinking yellow that points to a faulty PWM connection usually, check your connection and make sure the pwm cable pins are nice and lined up before inserting the cable.

Bad victors are usually very easy to diagnose due to smoke coming out of them, I've only had this happen when I was dumb and let some large metal swarf land in them.

[mgerber]

We thought we were having wiring problems on our 888s as well, until we realized that we had to push the PWMs in a little bit further than usual. Otherwise the CRIO's signal doesn't reach the Victors and they continue to blink yellow.

[Robby Unruh]

Originally Posted by Aren_Hill

If it just continues blinking yellow that points to a faulty PWM connection usually, check your connection and make sure the pwm cable pins are nice and lined up before inserting the cable.

Bad victors are usually very easy to diagnose due to smoke coming out of them, I've only had this happen when I was dumb and let some large metal swarf land in them.

We also have swapped a PWM cable from a working Victor in to one of the faulty ones and it still continued to blink, so we don't believe this is our issue. It's not smoking either. We really don't want to return these if we don't have to!

[Mk.32]

We tested on of ours, worked out of the box. If they are just blinking it is usually because of a loose cable.

[Ether]

Originally Posted by Robby Unruh

We also have swapped a PWM cable from a working Victor in to one of the faulty ones and it still continued to blink, so we don't believe this is our issue. It's not smoking either. We really don't want to return these if we don't have to!

Leave the cable plugged into the Victor, and unplug the other end from the DSC. Hook the signal and ground pins of the unplugged end to a cheap handheld digital multimeter that has a diode tester (e.g. Velleman DVM850BL). Post your results here.

[Ricky Q.]

Originally Posted by Robby Unruh

Our team just wired up our prototype bot and much to our surprise, we have 4 bad Victor 888s right out of the box. We are positive that our wiring is correct- it was done by a 4th year member and double checked time and time again. We have 6 more we got with our shipment and are going to test them tonight to see if they are good.

We plan on returning them and/or getting new ones, but have any other teams had an issue like this where multiple motors just seem to go bad?

These are directly out of the box. We bought them before build season started from VEX Pro.

If you're still having trouble after troubleshooting on your own make sure to give us a call at 903-453-0802 or emal support@vexrobotics.com and we can help you figure out what is going on and/or replace the Victors if necessary.

Best,
Ricky

[Joe Ross]

Compare a working Victor to a bad Victor. Is the PWM cable inserted to the same depth on both?

[Robby Unruh]

Originally Posted by Joe Ross

Compare a working Victor to a bad Victor. Is the PWM cable inserted to the same depth on both?

The PWM cables are pretty hard to settle in there, but they are hooked in. [Scratch this] We now believe it might be a defunct PD board. But essentially what is happening when we enable is:

• 2 Victors are solid yellow.
• 4 Victors continue to blink.
• The 4 blinking are wired to our CIM motor, and will not output any power.
• If we swap out one of the blinking Victors with a solid-light Victor, the motor gets power, as expected.

Certain slots could be busted on our PD board, we're still troubleshooting. (also, on hold with VEX Pro. Thanks Ricky!)

edit: disregard, our PD board is fine.

[Mark McLeod]

I have to ask the silly questions:

• Are the 3 Digital Sidecar power LEDs all brightly lit green?
• Do you have a second DSC you could try the PWM cables in (& 12v power & 37-pin cable)?
• Code opening all PWMs?

[Joe Ross]

Originally Posted by Robby Unruh

[*]The 4 blinking are wired to our CIM motor, and will not output any power.

Am I reading that correctly? Do you have 4 speed controllers wired to a single motor?

[Ether]

Originally Posted by Joe Ross

Am I reading that correctly? Do you have 4 speed controllers wired to a single motor?

You read my mind.

[Robby Unruh]

Originally Posted by Joe Ross

Am I reading that correctly? Do you have 4 speed controllers wired to a single motor?

No, we're using 2 AM Super Shifters. Each has 2 motors, each separately wired to it's own speed controller.