E501

Turn sign: effective for turn button

Trouble shooting procedure
1)Check resistance of mercury switch foot U5 on main board, when check the main board should be in vertical position: around 11.7K; When main board in horizontal position, the mercury inside U5 will cause short current: 0 Ω
2) Check C51’s resistance: 10K; supply power by 80V isolation transformer,test the voltage of two sides: 3.2V.
3) If the mercury switch is broken, adjust parameter of control box, set parameter 28th’ value to 1.