Before you recover Fanuc alarm 300, you must know what the cause of the alarm 300 in CNC Machining. Below are the cause of the alarm Fanuc 300
1. Pulse coder data has been lost, this can happen because the cable broke pulse coder.
2. Replacement pulse coder, if you change the pulse coder then when the engine in turn will display the alarm 300.
3. Backup battery is not good, the voltage drop.
Once you know the cause then you can check for parts each. If all is you check the next step is setting the parameters.
Fanuc O mate parameters 22 XXXX0000 bit 7 = X axis, bit 6 = Y axis, bit 5 = Z axis, bit 4 = 4th axis. Setting from 0 to 1 and then the machine restarts.
Fanuc 16/18/21 parameter 1815 bits 4 setting from 0 to 1
Maybe that's all I can hopefully help inform and useful.
Will you read my other articles Fanuc Backlash Parameter or Fanuc Alarm Codes