Roomba 560 Chraging error repair

My roomba 560 is making a charging error 3 prompt. I have reset it, taken it apart and cleaned it, cleaned battery contacts, gotten a new battery and finally reset with new battery and I still get this message. iRobot tech help just told me to buy a new one. Is there a replaceable part that has failed?
Thanks.

Thank you for the thorough answer. I have tried charging without the base.

Hi Joe,

This error could come from the robots charger or motherboard. Have you tested the output voltage of the robots power supply? You should obtain 22V from the charger and 2.8V from the contacts on the home base. Have you tried charging the robot without the home base? In some cases, there could be an issue with the home base.

If the voltage from the charger and home base are good, the problem is most likely with the robots motherboard. We unfortunately no longer sell the Roomba motherboard but, you can certainly find one with a research online. We do have a repair manual for replacing this part.