[quote=JCharlton;1189412]All of the above suggestions are good, to repeat:
- If the tube has been inserted a few times, replace it
This is a training opportunity. I find that students will usually assume that anything that plugs and unplugs has an almost unlimited insertion life. They will plug and unplug these connectors many times during debug or while assembling other things near the connector. They will not think twice about it, or tell anyone they did it. They just do not think it matters, but it does. Make sure all students working on the robot understand the importance of maintaining the integrity of these connections.