Yeah I have 10 of them. You can try reinstalling the sd card image and if that doesn't work you need to buy a new controller.
I broke down and bought a $10 3-speed fan from Walmart. I unplugged and removed the black fan from the Baikal X10, I put the Walmart fan in front of it.
do it efficient reduce the temperature compare with previously?
No, it doesn't reduce the temperature more efficiently. The miner is at my office, and I need a way to reduce the noise. If I could control the fan speed with the built-in fan, I would keep it, for sure. I am also mining Skein, which uses the least amount of watts, so as to produce the least amount of heat.
you can control the fan speed with this setting at sgminer options: baikal-fan (sgminer options) and 40 (value). theh it will be running at 40%. it is working for me since some months without problems.