Universal Robots UR3 Service Manual page 77

5. Service and Replacement of Parts
3. Disconnect the 2 wires for the energy eater and fan.
4. Remove the 2 nuts (M6) in the bottom of controller module.
5. Gently take out the controller module from the controller box.
6. Turn the module 90° counterclockwise and place it on the controller edge.
7. Cut the cable tie that tied to the robot cable, unplug the connectors from the Safety Control
Board and remove the cable.
8. Turn the module 180° clockwise and place it on the controller edge.
Service Manual 71 UR3