[Servo board XX](Power regeneration control board (No.XX)) P-N voltage too low. (for E0x series controllers)

Error handling: Motor power OFF.
Error reset: Possible.

Content: With the servo ON, the power regeneration control board detected an error: the PN voltage dropped continuously for 2ms. (Detected by the servo board)

Main causes:

1. An open circuit in the harness between the power supply unit, relay connector XRS-P, and power regeneration unit.

2. The power supply unit is faulty.

3. A problem with the power supply unit power board.

4. A problem with the servo board.

5. The power module for the power regeneration axis is faulty.

Countermeasures:

1. Check the wiring between the power supply unit, intermediate connector XRS-P, and power regeneration unit.

2. Replace the power supply unit.

3. Replace the power regeneration unit.

4. Replace the servo amplifier unit.