The cutting head moves download while auto-focusing or following

1.Possible cause analysis of failure:
a.Sensor fault or amplifier fault
b.Collision alarm
c.Wiring error
d.The metal plate being tested is not properly grounded to the machine.
a.Contact the cutting head with a metal object and observe whether the collision indicator on the amplifier and the indicator connected to the heightening box are on and,if so,eliminate sensing problems.If the indicator light is not on,the sensor fails.
b.Check wiring and plate grounding problems.