bq20z655 eval kit

Hi,

I have the bq20z655 eval kit wired to a static 5 bar LCD on TB5 and TB6. I have the mode set to LCD in CFG C.

I get the LEDs flashing at 20Hz but I have no backphase out of pin 12 "common" so LCD does not work.

Why is this and do you think I need to modify the eval pcb to remove the LEDs?

Thanks.