Error 4220 (Detail 121) – Inverter board converter circuit error

What does 4220 (D121) mean?

An error is detected within the converter circuit on the INV (Inverter) board. This indicates a critical internal hardware fault, typically requiring the replacement of the INV board.

• INV (Inverter) board failure

Click steps to track your progress.

1. 1

   This error points to an internal fault within the INV board's converter circuit.

2. 2

   If this error persists, the INV board likely needs to be replaced by a professional technician.

3. 3

   Contact a qualified technician for repair and part replacement as internal components are not user-serviceable.