Unilateral failure is generally caused by electromagnetic valve. Solenoid valve failure is likely to cause the control circuit is bad, it may also change the mechanical card. The specific test method is the first amount of the valve has no voltage. If the voltage on the valve to open the cleaning. Due to long-term use, for ask movable valve shaft of tens of thousands of have a little small impurities in the shaft galling cause stuck, resulting in operating table motion in one direction only.

2016.6.30