Well I swapped the drives and the problem persists on pump 2 now... Prior to swapped the drive I swapped two intermediary comm devices. One was the piece that connects the comm port cable receptacle to the drive, and the other is the piece that connects the LCD display and the 485 port wire to the drive. I swapped both of those and it didn't make a difference. Then I swapped both drives, reassigned addresses, fired it up. Now pump 1 works just fine. For a minute pump 2 was reporting RPM and wattage and all that, yet still saying communication error. I then rebooted the Intellicenter and then it lost everything. Back to how it was with pump 1 originally. So, I guess I need another drive. Any suggestions on how to obtain one? I wonder if there is a "wanted to buy parts from a busted pump" section on TFP lol.