Faulty PWM?

[Justin_302]

we were going over our board today and one of our PWMs was blinking orange. We changed the program, checked the breaker, and then we pulled off the PWM and replaced it with a good new one. BAM..it worked.has anyone else had a problem with faulty PWMS? and i was going to burn it until i realized that i could send it back in to first and probably get a new one...

[dez250]

You say a Faulty PWM, do you actually mean a Victor motor controller [pictured below]? If that is the item that you say is faulty i suspect that the problem was just the PWM Cable was not completly set in the connector.


http://www.ifirobotics.com/images/victor-884-250-a.gif

[Justin_302]

no no no.....we changed the pwm cable and it still didnt work. it is defently the PWM. it was brand new also...we had just pulled it out of its box a few days before. we have ruled out every possiblity. there are no metal shaving in it(we dont work with the board in it). we had another victor with a bad muffin fan. first needs to do some quality control.

[Sparks333]

Justin,
I am confused. There is no component on the robot called PWM. There is an electrical communications that uses PWM (hence PWM cables) and they are used frequently. There are also PWM devices, most notably the victors. There are also PWM ports on the robot controller. Please clarify your vocabulary! If you don't know it by any other name, then see if you can post a picture like dez did.

Sparks

[Shu Song]

I think that Justin is just calling the victors PWM's. We've been having that issue as well. One of vics would just always blink orange. We sent it in to FIRST for repairs, but they just sent it right back and said nothing wrong with it.

We had confirmed the defect with a working pwm cable connected to that victor, it was still blinking orange and getting no signal. I agree, FIRST really neds to do some quality control on these parts, because I would hate to have something like this happen at competition.

[dez250]

I agree, FIRST really needs to do some quality control on these parts, because I would hate to have something like this happen at competition.

Maybe if FIRST made these parts they could diagnose faults and problems. I would suggest next time when you have a unit you think that may be defective to contact Innovation First, Inc.

[dlavery]

I think that Justin is just calling the victors PWM's. We've been having that issue as well. One of vics would just always blink orange. We sent it in to FIRST for repairs, but they just sent it right back and said nothing wrong with it.

If you sent it to FIRST for diagnosis and repair, it is no wonder they just sent it back to you. The Victor Speed Controllers (and Spike Relays, and RC, and OI, etc.) are all Innovation First, Inc. products. As noted in Section 5.4.3 of the manual, all IFI products need to be sent back to them - not FIRST - for replacement or repair.

Historically, IFI does a pretty good job of quality control. Occasionally there have been a very few bad units that have slipped through. But many times the "bad units" have been damaged after leaving IFI (during shipping, packing into the kits, etc.) or by the occasional fat-fingered-software-geek-pretending-to-be-a-mechanical-designer that accidently shoves a screwdriver into the turning fan blades and then quickly puts the broken unit down on the table and walks away while innocently asking "hey, who broke the Victor?" (don't ask me how I know about this :) )

Anyway, back to the original problem. Upon occasion, we noticed that the Victors will sometimes (not every time, or even the majority of times, just occasionally) show orange if the PWM cable is inserted backwards into the plug. We found this out when we were using some older PWM cables that had smaller plastic ends that were not keyed, and fairly easy to insert backwards by mistake. I know this seems like a simple, basic item, but check to be sure that the PWM cables are installed correctly and completely seated on the pins.

-dave

[Sparks333]

or by the occasional fat-fingered-software-geek-pretending-to-be-a-mechanical-designer that accidently shoves a screwdriver into the turning fan blades and then quickly puts the broken unit down on the table and walks away while innocently asking "hey, who broke the Victor?" (don't ask me how I know about this :) )

-dave

Everyone,
Okay, so now that it's established that PWM = Victor, I am up to date. By the way, Dave, the above quote is a great one, and I completely know what you mean. Of course, if a mechanical designer were to try programming...

Furthermore: Justin, we have had similar problems. The newer vics have the deeper PWM sockets than last years, which is a gift and a curse (they are harder to get the PWM cables out, but also harder to get them in!) Make sure your pins are all straight and the right pins go to the right holes, then try inserting. This is not an uncommon problem.

Sparks

[Bcahn836]

no no no.....we changed the pwm cable and it still didnt work. it is defently the PWM. it was brand new also...we had just pulled it out of its box a few days before. we have ruled out every possiblity. there are no metal shaving in it(we dont work with the board in it). we had another victor with a bad muffin fan. first needs to do some quality control.


We had the same problem with the PWM cable, going to the left transmission. We to checked the fuses, programming, motor controller, joystick, Everything and it was the cable.

[Al Skierkiewicz]

Many teams have encountered similar problems this year. The PWM cables need to be fully seated in the sockets. The large shoulder on the PWM socket makes this difficult to see but you need to take the time to get it in right. It is also possible to misalign one or more of the pins as you insert the connector and they miss the intended target. When in doubt compare the height of the connetor body to another controller to make sure you are fully inserted.

[Chris Hibner]

Many teams have encountered similar problems this year. The PWM cables need to be fully seated in the sockets. The large shoulder on the PWM socket makes this difficult to see but you need to take the time to get it in right. It is also possible to misalign one or more of the pins as you insert the connector and they miss the intended target. When in doubt compare the height of the connetor body to another controller to make sure you are fully inserted.

Yes, we have had these problems this year. I never remember having problems like this in past years, but we have had this problem on 5 different occasions this year. I wonder what's different about this year - did IFI switch to a different supplier?

[Justin_302]

we tried changing out the wires. they were not backwards and not bent or broken...and the wires were brandnew

[Adam Krajewski]

It seems to me that the plastic housings on the 2005 "red" generation Victor 884s are much looser in their tolerances than previous generations of 883s and 884s. This could be why there is a misalignment problem. I prefer the older "blue" 884s because of this.

Once you get the PWM cable properly seated, one of these will help it stay that way:
http://robotcombat.com/images/store_pwmclips_lg.jpg
You can buy them here: http://robotcombat.com/marketplace_ifi_esc.html

[Shu Song]

Sorry, I misspoke. I meant that we sent our vic back to IFI and returned it and said that there was no problem. Sorry for the confusion.

[Chris Hibner]

we tried changing out the wires. they were not backwards and not bent or broken...and the wires were brandnew

Same with us - we still had problems. We tried spreading the outside pins of the PWM cable just a little and also bending the pins in one direction. After a few times trying, we were able to get it to work.

[Alan Anderson]

we tried changing out the wires. they were not backwards and not bent or broken...and the wires were brandnew
Yeah, us too.

But the problem was still that the pins on the pwm cable weren't going into the socket on the Victor properly. It takes patience and not a little luck to get them seated.

[Justin_302]

according to first, this is a problem. when you plug the data cables in, if not perfectly straight, the pin will become crooked. the problem is basicly the pwm data cable. so if any other teams have this problem, use new data cables and be careful pluging them in

[408Oxidation]

We had the same problem....
All 4 Victors were blinking orange, but for some reason unplugging and plugging back in the PWM cable worked for 3 of them, even though it took about 10 tries to get it working again. One is still blinking, however. The pins are straight, the cable is brand new, and the victor still wont go to solid orange. We can run fine off of 2 Victors and 2 spikes, but it would be easier to use 4 victors. Any ideas?

[ConKbot of Doom]

Maybe the problem is the straight pins, bend them just a tad, just enough so that when they go in, they push make better contact with the connector. If they don't work one way, bend them a tad in the other direction. The connections for the victors have been really flaky this year. But I have found that that helps quite a bit.

[kevinw]

Anyone know who at IFI we could talk to about the differences in the 884's from last year and the 884's from this year? Last year's seem to be a whole lot easier to plug the cables into reliably. Maybe they'll bring the old 884's as replacements to the competitions. Or go back to the old ones for next year.

[Al Skierkiewicz]

Anyone know who at IFI we could talk to about the differences in the 884's from last year and the 884's from this year? Last year's seem to be a whole lot easier to plug the cables into reliably. Maybe they'll bring the old 884's as replacements to the competitions. Or go back to the old ones for next year.
There will be IFI people at the regionals but I know that they read these boards. I am betting that there will be some changes in the controllers by next year including bringing back the wiring markings and better PWM insertion.

[Justin_302]

thats good news to hear