Mouse, keyboard sudden failure

We have been using DELL industrial machine, 24 hours is not the kind of shutdown, but from time to time there will be a mouse, keyboard (U I) failure, you will be able to re-plug, and do not know if this is Why, please help us find out the reasons.

Me also, under the resumption or unplug and then plug in all lines, Later, it can not stand on the Na Quxiu that is not very good contacts inside the