Advice in Fixing Hall Sensor Error on a Brushless Rear Drive Hub (Photo of motor)

[gembike223]

I have a Vilano Neutron (36v 250w folding fat bike), and it uses a king meter km529. Currently, when I turn on the bike it flashes Error 24 which I have research indicates a "Hall Sensor" error either due to a loose wire or burnt out hall sensor. Before this error, I used it for a relatively long (~1hr constantly) uphill which was around 15% slope, so i think i might have pushed it abit too hard. I'm not sure whether that was what was the caused of this.

Anyway, i did open up the motor and i'm 99% sure I found what is wrong but just want to double check what I need to do (and where) to fix it. Please see these 2 photos:

As you can see, the circled GREEN wire is not connected at all. But I need to figure out where to solder it back to. Also I am wondering what the heck is all that "melted looking" black stuff? Is that intentional from the manufacturer to "hold" things down? I wonder what could have caused the green wire connection to come off.

Any advice would be appreciated. thanks!

 

[harryS]

Motor got so hot that the solder melted? That would be around 370F which is pretty hot for a Hall effect sensor too. I dunno what that black goop was. Maybe melted rubber? There is a product called liquid rubber which might have been used to seal the wire bundle.

We can see where the yellow and blue hall wires are still connected, and how the three hall devices connect to the board. My conclusion is that the green wire would have gone to the pad you marked with an "A".

What I would do is re-solder the green wire. Then I would put five volts across red/black and check the Hall outputs before putting the cover back on. Check the speed sensor circuit (white wire) on the other little board too.

 

[gembike223]

"Check the speed sensor circuit (white wire) on the other little board too."

Thanks, where is the other little board..? yes i do know that a white wire comes out, but havent actually seen it inside here.

 

[harryS]

Other board is shown in the second picture,