Throttle wires shorted - repair controller?

[veloman]

Solved!

I was stupid and didn't think I had to cover the yellow and brown throttle wires on this HUAYUXINFENG 14amp 36v brushless controller. It no longer worked/ turned on at all after this. I opened it up and see something that I THINK could be the damage: see picture - the little black square that has 3 leads coming off the right side. The middle one looks like it's broken. Could this be it - should I try connecting this?

Or will this lead to diaster?

 

[amberwolf]

the middle lead is simply unused, if you're referring to the one labelled LM317.

I would guess that if there is damage, it is to the 5V regulator, which is probably downstream of this. and could even be the similar one in the lower right corner. You'd have to start measuring voltages at the input to the LM317, it's output, and then follow that out to the 5V outputs to throttle, motor halls, etc., to see if that's working. To get an idea of the circuit invovled, take a look at just about any contorller repair involving the low-voltage (usually 12V) and 5V circuits.

 

[ZOMGVTEK]

If you are talking about the fairly large reg in the lower right with the 'disconnected' center terminal, thats definitely not your problem. That pin is connected through the heat sink, right on the board.

What exactly happened that caused it to not work?

 

[auraslip]

Did this on an infenion.

First step, as AW said, is to check 5v bus.

On mine, there was a simple little diode designed to short and bull the 5v line down to ground in the event of a short. I just had to remove/replace it.

 

[veloman]

Okay, it's not what I originally thought then - the LM317.

Here's a pic of the back, which looks to have something burnt, in the center of the picture. On the flipside, there is nothing connecting to the burnt area through the board.

After the wires shorted, the controller did not respond to any throttle input. The throttle works fine on a different controller.

I will attach some more pics, can anyone tell me if they notice what might be this 5v regulator?

 

[amberwolf]

Yes, that trace is burned thru. You should try wiring around it (scrape some green off to expose copper on each side of the burn, on that trace only, and solder a bit of wire across the gap), and then see if it powers on.

Keep in mind that if something else down the line from it is shorted internally, it could vaporize once the repair to the trace is made. As long as nothing blew in the controller except the trace, directly from the short at those wires externally, then fixing the trace will fix the problem.

BTW, I can see plenty of things that connect to the burned area on either side of the gap in the trace, so I'm not sure what you meant by "On the flipside, there is nothing connecting to the burnt area through the board." :?

 

[veloman]

Well, I am a complete noob, I'm sure my statement was incorrect lol


I am considering donating this if you or anyone else is interested. My skills for this stuff are pretty limited.

 

[amberwolf]

If you have a soldering iron, it is certainly worth first just jumpering across that burned trace--it will probably fix it.

If it doesn't, well, you can worry about that afterward. :lol:

 

[dnmun]

this is how you learn. you should at least try to fix it. giving up is lame, and so middle class consumer throwaway culture burdened. that's what george did, and so many others.

it looks like that is the Vcc running over to the input power resistors. you should be able to follow the traces and see what that connects, but i doubt if you have any voltage on the legs of the power resistors, so you can bridge it with a wire, no need to even fill the trace, just a tiny wire soldered at each end where you can get the soldering iron. then check the output voltage on the LM317 regulator.

 

[veloman]

OKay, I gave it a shot, it's not pretty, this small stuff is really difficult to work with. Here's what it looks like now:

I will plug it in soon and see what happens.

 

[veloman]

It's alive.

It works again. Wowza.... I repaired something.

Thanks guys!

 

[dnmun]

really does your ego good doesn't it?

i finally got the floor in to the closet expansion i started just before kingfish came through. one small step for man, now to get the shower stall upstairs 18' up through the bathroom window i tore out. 34" wide rough framing opening of the window, 32" wide 72" long shower stall 160 lbs, glad my neighbor is strong as a horse. the stall is too big for the stairs or the bathroom door, good thing i had torn out all the windows. what a lotta work. nothing for the ego. the floor helps.

 

[veloman]

Did you use some kind of hoist? Sounds fun and challenging :lol:

 

[dnmun]

it won't be fun. will use a rope and have my neighbor pull from upstairs and i will climb the ladder from inside the stall holding the weight on my shoulders while he pulls it up the ladder. it has to go upside down that way. base at the top with the rope through the drain hole. with me pushing up the base from inside.

so glad it works for you, always a great feeling. that trace has full battery voltage so when it shorted, it acted like a fuse and blew where the trace was narrowest.