Hi all, we have a UR3 robot and it was idle for about a year and i was tasked with reactivating this project. It started ok and i managed to get it to run several programs quite happily. Then all of a sudden the power to the robot stopped and it wont restart because of the C4A16 error (Communication with joint 4 lost). i have performed the reboot sequence and visually checked the connections in joint 4. the software is the polyscope 3.5 in the robot. Is there a way to manually move the joints to maybe a different place to reactivate the joint or any other fixes for this. I saw there was a post about a UR5 but i couldnt see the PDF link and it didnt seem to have a fix.

Thanks