你是不是panning那个小knob锁死了？

手册上说：

Mud or salt water shouldbe lightly rinsed off with fresh water and then thoroughly dried. DO NOT submerge the ballhead when washing and do not direct a high-pressure stream of water at the ballhead.

All the knobs are captive, meaning they cannot come off without damaging them so do not attempt to remove the knobs. If fine sand/grit fouls the knob, simply run a gentle stream of water around the knob while rotating it one-half turn back and forth.

我用BH-55至少有4-5年了，还真没有遇到像你这个难题，希望你能早日解决。