View Full Version : 4 Known Bad Victor 888s
Robby Unruh
30-01-2013, 17:18
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
30-01-2013, 17:20
What behavior are you seeing from the "bad" victors? could it be a calibration issue?
Robby Unruh
30-01-2013, 17:23
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
30-01-2013, 17:29
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.
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
30-01-2013, 17:30
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!
We tested on of ours, worked out of the box. If they are just blinking it is usually because of a loose cable.
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 (http://www.allspectrum.com/velleman/DVM850BL/dvm850blgb.pdf)). Post your results here.
Ricky Q.
30-01-2013, 18:09
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
30-01-2013, 18:20
Compare a working Victor to a bad Victor. Is the PWM cable inserted to the same depth on both?
Robby Unruh
30-01-2013, 18:38
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
30-01-2013, 19:06
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
30-01-2013, 19:08
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?
Am I reading that correctly? Do you have 4 speed controllers wired to a single motor?
You read my mind.
Robby Unruh
30-01-2013, 19:22
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.
Al Skierkiewicz
31-01-2013, 08:46
Robby,
If the Victor has an illuminated LED then the PD is working. Everything sounds like the PWM cable is not full inserted. These can be tricky as it is possible for the pins to miss the female connector inside the block. Once fully inserted, less than 1/8 inch of the PWM block is visible above the shoulder of the Victor housing. It is possible to fully insert the connector and still miss the female connector.
ctccromer
31-01-2013, 09:01
We have never had issues with Victors until this year. We have one that may or may not be broken (turned on the robot one day and only one side of the drivetrain moved). We've yet to fully look into it, but at first glance it does appear to be broken. It was one from last year though, not right out of the box
The fan is not working on one of our 888s.
Al Skierkiewicz
31-01-2013, 09:04
Taylor,
Nine times out of ten, the fan wire was crimped before the wire was stripped.
I'd check the following:
1) Whether PWM connector is properly inserted into the Victor. It is easy to misalign. It often appears to be plugged in properly, but the pins don't actually go into the connector inside the Victor housing, but slide off the side instead. Remove the PWM connector and see if the pins are bent all to one side slightly. If so, the connector was plugged in incorrectly. Straighten the pins, and try again. Wiggle the connector slightly as you insert it. The connector should take very little force to fully seat. If you have to push hard, you've missed the connector.
2) Check the ribbon cable from the Digital Sidecar to the cRIO module. If some of the wires were not fully crimped in the connector, some of your DSC pins won't work. This is likely the case if some of your PWM ports don't seem to be working. You can verify this quickly by connecting one of your blinking Victors to a PWM port that was successfully driving a non-blinking Victor.
Robby Unruh
31-01-2013, 09:52
Thanks for all the replies everyone.
Our team decided to attribute the cause to internal damage. Once we swapped out the Victors with our spares, it ran fine. (and if you're curious, has been posted here (http://youtu.be/PfqUNThlXfc)) We are still unsure as to what might have caused the damage.
After we get to test the supposed "bad" Victors a little more, we are going to call VEX again and see what we can do about shipping these back and/or getting new ones.
Our team decided to attribute the cause to internal damage. ... We are still unsure as to what might have caused the damage.
Did you ever run the simple diode test on the Vic's PWM input?
Robby Unruh
31-01-2013, 12:38
Did you ever run the simple diode test on the Vic's PWM input?
On the Victor's PWM input slot? We checked the output, and although the Victor was receiving input, the output remained at 0 volts. Which could have been a loose PWM cable, but does not explain how swapping them out works.
On the Victor's PWM input slot?
Yes. As explained earlier here (http://www.chiefdelphi.com/forums/showpost.php?p=1224779&postcount=8).
We checked the output, and although the Victor was receiving input, the output remained at 0 volts.
How do you know the Victor was receiving input if you didn't test it?
Which could have been a loose PWM cable, but does not explain how swapping them out works.
An improperly seated PWM cable would explain it (on a Vic that's a little more finicky about how the input cable is plugged in).
Robby Unruh
31-01-2013, 13:09
An improperly seated PWM cable would explain it (on a Vic that's a little more finicky about how the input cable is plugged in).
The PWM cable could have been loose, but I don't think this is the case.
We also had done a bench build while we were swapping them out, hooking each Victor up to a motor we knew worked before placing it back on the robot. I believe it's safe to say four of the twelve we have just don't work. We greatly appreciate your input, though.
Paul Copioli
31-01-2013, 15:11
The PWM cable could have been loose, but I don't think this is the case.
We also had done a bench build while we were swapping them out, hooking each Victor up to a motor we knew worked before placing it back on the robot. I believe it's safe to say four of the twelve we have just don't work. We greatly appreciate your input, though.
If you call customer service, they will walk you through troubleshooting and replace if the Victors are bad out of the box.
I can tell you though if the LED is blinking orange, then the Victor thinks it is not getting any input. If the light was solid or off, then I may be inclined to think the Victor is bad. However, the Victor behaved as I would expect it to when the light is blinking orange. The problem could still be with the Victor, but at the input side.
The blinking orange means the Victor is not getting a valid PWM signal.
151 Tough Techs
07-02-2013, 16:12
We've been having issues with out Victors as well. After some research we found out that if you shave down the sides of the shroud of the PWM cables they will fit into the holes of the Victors. Our pins were not connecting to the inputs in the victor because the shroud of the cables are too big. Vex says that if you are having issues with the Victors than to shave down the sides of your PWM cables. Hope this helps, good luck!
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