Bafang BBS01 CAN throttle not working

[Jakuda87]

Ok so only marked ends lead to ground.
Green marked SMD gives about 2Ohms, for all other ones multimeter shows OL

 

[DPC18RI]

To be sure, there is no short between TPP and ground?
So only the ones you marked with black line have ground connection. And the righthand side of burned component is not connected to ground?

 

[Jakuda87]

nope, no more connections to ground here

 

[DPC18RI]

Is on the picture, in the orange circle, is there damage too? Be careful there because that big capacitor can be charged with battery voltage! The thing is maybe the controller can be repaired but you need to follow the traces from component to component until you reach the source of the 5V. It can't be done from a distance via the pictures.
If you can't do it then the solution is to find someone who can or buy a new controller. Where did you bought this one?

 

[Jakuda87]

no, it was just a debris. It's resistance is about 2 Ohms

 

[DPC18RI]

Can you post a picture under good light from that additional board where the blue wire arrives? And is there a marking for the blue wire, which letters if any? It keeps puzzling me because on some other Bafang canbus controllers the additional board is for lights output.

 

[Jakuda87]

here you go



As I've said- this blue wire is only one that goes separately from LCD harness (leads to pin 1).

This harness has also light wires- black goes to ground, and red to pin marked BREAK (on the other side of controller)

 

[DPC18RI]

Just below additional board, component marked 78M05 can you measure any voltage on the left pin and on the right pin.

 

[Jakuda87]

right pin goes to ground. between two is 0v

 

[DPC18RI]

Not between the 2! Measure between ground and left pin. That short middle pin no need to measure. Then measure between ground and pin on the right. Make sure display is on. left pin should be input voltage, right pin should be (normally) 5V out.
To be clear as possible, position left and right orientation just like on your picture..

 

[Jakuda87]

like I've said right pin goes to ground

 

[DPC18RI]

Do you have any voltage between ground and left pin? Which is input pin. If your right pin is ground like you said then it's probably shorted. Remove battery and measure in continuity mode between ground and Right pin. If zero Ohms it's probably shorted. If it's possible desolder it and afterwards measure on the pcb in continuity mode between ground and that right solderpad. If still zero ohm then you still have a short between there and the TPP pin.

Added; if it's to difficult to desolder, heat up the left pin and lift it 1mm and do the same for right pin. Then you can measure as mentioned above without removing the component...

 

[Jakuda87]

ok I removed this mosfet the hard way.
Still right pin and corresponding capacitors? are shorted to ground on both sides

 

[DPC18RI]

How do you mean the hard way? Destroyed it ?? If that 78M05 is completely removed then there should be no short on right solderpad but you say it still is so you have to follow the trace from that right solderpad and test the components along the trace for shorts.

 

[Jakuda87]

Ohh it goes both ways through a few components.
Unless I you will guide me step by step I will need to give it to my friend who is more fluent with this stuff.

 

[DPC18RI]

It looks like it's better that you give the controller to your friend if he has some knowledge regarding electronics. Maybe he is able to repair it for you. About BBS01 canbus controllers i did find one on a webshop with the same connectors as yours.