MP3 Controller, popped capaciter, can you identify?

[betarambo]

I accidentily put 48V into one of the throttle hall inputs on the internal control on the Magic Pie III. This stopped the controller from spinning the wheel but the battery lights on the throttle still light. I took the controller apart and found a blown capacitor ( I think it is a capacitor, is was a yelow block). It was pretty charred and burned.
We unsoldered it from the board. Now, I would like to replace the component so that the controller will work again. It appears that Golden Motor does not release schematics on this stuff (probably to protect their intellectual property) so I have no way to figure out what to replace the burnt part with.
The cap is between the first (or last) fet and a chip. It appears to be the largest squarish yellow component on the board.

[Morgen 3Eman]

So tell us the story about how you managed to get 48 VDC on the throttle signal wire! 

The same component has made my Pie controller into a dead short emulator twice.  I had no idea it was yellow.  And I didn't even get a story to tell...

TTFN,
Dennis

[betarambo]

The story really isn't that good.

1. Ordered MP3 kit with twist throttle.
2. Received kit with thumb throttle.
3. Asked for twist throttle to be sent.
4. Received twist throttle but not for MP3 so it had the worng connector.
5. Determined that after sending me the wrong throttle two times, the dealer was not going to send me the right throttle.
6. Decided to wire the wrong throttle in.
7. Wire colors were all different.
8. Ended up touching the 48V from the battery that drives the battery guage or maybe for use on the switch on the throttle to one of the hall inputs on the controller.

Are you saying you have had two of these controllers fail and it was that particular component? Did you just replace the controller each time?

[skylinenitro]

If it was the hall input wire, there should be two more like it.  Can you trace the other two hall wires and see what caps they connect to?  Ideally, there should be three of those caps, all with the same specs.  Can you read on the other two caps what voltage and capacitance it is?

I'm guessing that they are less than 40v, maybe around 18v?  Also trace the solder lines from that blown cap and see what else it touches and see if those are charred or blown.

Can you get a picture of the bottom of that blown cap? 

Also, is there writing near that cap that says anything like "C12" or "R34"?

[betarambo]

It appears to be the only component like it on the board so it must be a bit downstream from the hall input. I looked for labeling on the board to tell me c something or r something but it was oddly just about the only unlabeled component, thus I am not sure if it is a capacitor or what.
I looked around the entire board and saw no other damaged components. I tried to trace it but couldn't follow it. I will try again.
I will see if I can get a picture of the bottom of the component. It is pretty bare so I am not sure what good it will do, but I am willing to do anything to get help. I may have to dig out a real camera as my phone can't focus in that close.

[betarambo]

Picture of bottom of component. Note that it had solder pads on both ends but you only see one as the other peeled off during removal.

[Morgen 3Eman]

I had two MP-3 controllers fail with very little usage.  No 48v input injection was required.  They both turned into shorts on first use after the battery was charged.  The same component failed on both.   The first one was replaced by GM China, and after the second one blew I didn't want another one.  I'm awaiting delivery of a Lyen controller.   I'm hoping it is more reliable:)

TTFN,
Dennis

[skylinenitro]

It must be a flux capacitor, or some dilithium crystals...  Too bad GM doesnt help with this.

Maybe a fourm member with a working MPIII (pun) can show us what this part looks like from their pie?

[betarambo]

Being on a short deadline (youth nationals are Friday) I decided I had nothing to lose. My buddy and I thought maybe this component was a filter so maybe it would run without it if not perfectly. It was shorted after it blew. So we pulled it out and tried to run. This resulted in a  runaway motor as soon as the battery was connected even with no other wires connected. It ran for half a second before I unhooked the batteries. It fried a leg off of one of the FETs.
On the bright side, I guess it doesn't matter what the first component problem was now!
So I guess my daughter will ride her old bike at the nationals and I will sort out a Lyens controller later.
Seriously bummed...
 

[Bikemad]

It must be a flux capacitor, or some dilithium crystals...  Too bad GM doesnt help with this.

Maybe a fourm member with a working MPIII (pun) can show us what this part looks like from their pie?

From your last post I guess it's no longer relevant now, but according to Google a 476K is a 47uF 6.3V 10% Capacitor:



I don't suppose it would have made any difference if I had been able to find this out sooner.

You did a great job on the axle plates though.

Alan
 

[betarambo]

Alan, you rock! Yes, it might have helped sooner, but I still might be able to find the cap and the FET tomorrow and get back in business. It's worth a shot.

Waiting to hear back from Lyen and see if he can overnight me a controller and maybe I can put it together when we get to the nationals.

Thanks on the comment about the axle plates. It was a team effort with input from a lot of folks and some very cool machinists at work who squeezed it in. They really worked out slick.