text: <s>[INST] Power Flex 755 intermittant comm loss Summary: Drive stops communicating randomlyCurious if anyone else has had this issue with the imbedded Ethernet cards on there 755s. This drive is part of a skid where the 5 drives work together off a master drive. And the drive runs fine but it looses communication intermittently and kicks the operators out of auto and makes them use the machine in manual. Ive tested the Ethernet cable going to the drive, ive changed the main control board, plugged the cable into a different port on the Allen Bradley switch to no avail. Ended up changing the whole drive out which fixed it. I am curious what would cause an intermittent issue like this? Any insight would be appreciated [/INST] No good answer. Changing out the main control board should have done the trick. It's possible the drive back-plane was bad. We've seen this once I think, and I think someone else commented on this in the forum. You've got it solved this time. I do not think it is a design defect. You say you tested the cable. Did you flat-out replace it? Was the cable commercial, or did you make up both ends? Was the cable rated for 600V and double-shielded (foil and braided shield)? \\n </s>