E7— motor HALL signal error

( when the power on HALL_A HALL_B HALL_C signal is low or high level)

Steps:
Check whether the encoder socket  connect well with main control encoder socket or not(whether there is dust inside encoder or not)
Check the impedance of pin 2 to pin 3(ground) of U3 of the encoder board: about 1.2M ; ( the standby voltage : switch between 0V with 5.1V with the raster angle is different); the impedance of pin 4 to pin 3(ground) of U3: around 20K (the standby voltage : 1.2V), whether pin 2 conduct with J1(pin 1 ) of U3 ( remarks : when encoder is connected with the main control ,the above impedance is different )
Check the impedance of pin 2 to pin 3(ground) of U4 of the encoder board: about 1.2M ; ( the standby voltage : switch between 0V with 5.1V with the raster angle is different); ); the impedance of pin 4 to pin 3(ground) of U4: about 20K (the standby voltage : 1.2V); whether pin 2 conduct with J1(pin 1 ) of U4( remarks: when encoder is connected with the main control ,the above impedance is different )
Check the impedance of pin 2 to pin 3(ground) of U5 of the encoder board: about 1.2M ; ( the standby voltage :switch between 0V with 5.1V with the raster angle is different); the impedance of pin 4 to pin 3(ground) of U5 : about 20K (the standby voltage : 1.2V), whether pin 2 conduct with J1(pin3) of U5 ( remarks : when encoder is connected with the main control ,the above impedance is different )

4) Check the two-terminal impedance of C29 on main control board: about 11K .(Standby voltage:5.1V); impedance of U2(38 pin) or U6(14 pin) to C4 negative terminal: around 3M (Standby voltage:3.2V)
5) Check the two-terminal impedance of C39 on main control board: : about 11K.(Standby voltage:5.1V);impedance of U2(52 pin) or U6(18 pin) to C4 negative terminal: around 3M(Standby voltage:3.2V)·
6) Check the two-terminal impedance of C41 on main control board : about 11K.(Standby voltage:5.1V); impedance of U2(64 pin) or U6(7 pin) to C4 negative terminal: around 3M (Standby voltage:3.2V)