I have an IMAX B6 that I use for everything that needs charging. My 3D prints benefit from these batteries, so I am posting the repair guide here.
My IMAX B6 was working fine until one day it began to show “temp error” and with the balance board unhooked it showed up as “REVERSE POLARITY”. I decided to take it apart, and find the issue.
It didn’t take long to find the broken trace on the back of the PCB. It was a simple tear down of screws on both end caps, then removing the screws holding the board down. Your board could have broken in the same spot, or elsewhere. You should look for broken traces or burnt components.
The trace was broken on the back of the board near the balance port. I decided to scrape back some of the mask, and apply solder to the remaining trace.
Once the trace was tinned, I took a piece of silicone wire cut to size and tinned both ends. Then using tweasers to hold the tiny wire, I soldered both ends to each side of the trace.
Then I applied DC power to see if the error message had gone away. Once verifying it worked, I applied some hot glue to the wire to hold it in place, and on top of the exposed trace and wire which will sit under tye mosfet. I wanted to avoid electrical contact between those two components.
Now I have a repaired IMAX B6 and I can charge my LiPO batteries and continue making neat 3D Prints and FPV Quadcopter parts!