bk 9920 problem... help needed before returning product...

SJCRSS, I tried to do it, it works until i unplug the black jumper... after that it doesn't work anymore... what is strange is that i have my servo at 6V with the rx pack + black jumper plugged ang red wire unplugged... i don't want to kill my controler, therefore i wait for an answer from BKelectronics...
The only possibility that i have today is to run w/o the bec enabled (red wire cut), but with a rx pack and black jumper plugged... It's the only setting that work...