E8— Motor stuck running

(motor running speed continuous 2s less than 25rpm or the current more than 10A)

Step of Solution：
This error happened when work in thick materials, please enter Ⅱ parameter adjust no. 22(Different thickness materials with different parameters,it depands on the actual material)
First make sure the head mechanical angle is no problem, then check if the contact between power socket and electrical contact is well
Judging whether the motor is working or not: using a multimeter (Ω block) to measure motor socket pin 4 and pin1, 2, 3  whether there is short-circuit，or whether the impedance among motor three-phase U [3], V [2], W [1] is same issue.
check the impedance between the main control board U8 pin 2~7  to pin12 : respectively at around 0.7M, standby voltage 3.8V
Check the Impedance  between the main control board U8 pin14, 15, 16  to pin12 : around 10K, standby voltage : 0V
Check the Impedance  between the main control board U8 pin1 to pin12 : around  2.4M,standby voltage:15V
Check the Impedance  between the main control board U8 pin10 to pin12: about 1K , standby voltage: low frequency(when the motor running is high)
Check  the two terminals impedance of main control board D27 : around 2.4M: standby voltage: 15V
Check the Impedance between the main control board Q3~Q8 pin1 to pin3 : around 10K
Check the impedance between encoder U6  pin3, 6 to pin2 : around 26K; standby voltage: 5.1V. Whether the U6  pin3, 6 and the J1 (pin5, pin7 )  connect with the main control socket CN4 (pin5, 7)
If the above detections are normal just change the U8