Some keys not working of CNC controller

There are some keys on the CNC controller not working, includes Spindle Forward, Spindle Backward, Spindle Stop, Coolant Pumps. But the CNC machine runs well under Auto mode.

This problem happened before, changed the CNC software and main board, the CNC machine resumed, but after about 5 days, the problem come again.

Check all the outer wiring and they are fine, the “B” key is normal, and we found the not working key are using the same cable, as there is no other keys’ problem, so this should be the CNC internal keyboard wiring problem.

Check by universal meter and found there is an open circuit between the keyboard to the main board, change the cable and the CNC machine back to normal.