The correct C axis Home process are as following:
Rotary table turn CW direction until the Dog (M5 screw) to find the C axis sensor. Then, the sensor send a singal to controller and ask C axis servo motor reverse turn (CCW) to find the encoder basic (0) point.
Finally, C axis servo motor turn CW at C axis offset value (parameter 886 setting C axis Home offset) .
The checking procedure is to loosen the 4 pcs M5 screws on cover of rotary table then take off the C axis cover to check the C axis sensor at right/up corner .
As for how to check the C axis sensor is normal or not ? Just check before excute C axis Home, the sensor should be OFF, the sensor just light ON a little period during a step M5 screw Dog goes in the sensor top area, then the sensor must OFF during C axis reverse turn (CCW), then turn CW to C axis offset value (Light should be off).
You just need to open cover of C axis then adjust sensor position backward a little and confirm the C Home process OK. then the trouble will go away. Hereby we show the viedo following for your reference.
PS: The C axis sensor normally work during 4mm distance , it mean if any steel (iron) material at 4mm range of the sensor , The sensor will light ON.
As for the parameter NO. 886 setting value , It’s only for C axis offset angle after C axis go to Home zero position. Set 58642 (58.642 degree) mean after C axis Zero position turn 58.642 to target position .
1) Loose the screws of rotary table then take off the C axis cover to check the C axis sensor at right/up corner
2) Adjust sensor position backward a little and confirm the C Home process OK