[Cause]
The teaching pendant is invalid when the mode switch is set to T1 or T2. Or it may be caused by hardware failure.
[Countermeasure]
1. While teaching operation is in progress, set the enable/disable switch of the teaching pendant to enabled. In other cases, switch the mode switch to AUTO mode.
2. Replace the teaching pendant.
3. Replace the teach pendant cable.
4. Replace the mode switch.
5. Replace the emergency stop board.
6. Replace the 6 axis servo amplifier. For details, please take appropriate measures according to "Troubleshooting based on alarm codes" in the control device maintenance manual corresponding to the control device used.