Check whether the control system is in the program test state:
Check whether the status LED for program test on the MCP is lit
(it must be off)
Check whether the PRT icon appears in the program status bar
on the PPU screen (it must be deactivated)
Perform the above diagnostic steps for case 1 to check the spindle if the fault still exists.
Check whether there is interference between the connection cables. Make sure you route the power cables and signal
If you use an analog spindle, check the interface X54 on the back of
the PPU for the following:
Whether the interface is loose or damaged
Whether the connections have bad contact
Check whether the connection cable to the spindle drive is loose or whether the drive is damaged.