Cause: Control Circuit Error comes when there is a self-diagnostic error in the control circuit or connector on the operator is damaged. This fault also comes when there is hardware issue in drive.

cpf21 yaskawa indicates Control Circuit Error. This means there is an issues with the RAM, FLASH memory, watchdog circuit, or the internal clock of the drive's control board.

Troubleshooting Steps:

Follow these steps to correct cpf21 yaskawa:

• Remove Run Command and Reset: Ensure the run command to the drive is removed and try pressing the RESET key on the keypad. If the fault persists, proceed to the next step.
• Remove Power: Completely remove the power supply to the drive.
• Remove Control Wiring and Option Boards: Disconnect all control wiring and any optional boards that are attached to the drive.
• Inspect Control Board: Carefully examine the control board for any signs of burn marks or corrosion. If damage is visible, the control board needs replacement.