I've got a B250 in the field with about 750k copies on. It suddenly doesn't want to detect the Duplex unit. Tried all the boards, upgraded F/W to latest version, replace Power Supply Unit and even another Duplex unit. Still no luck. If you open Dupllex door it doesn't show cover open, nor does it detect a jam if you create a jam in the Duplex. Any suggestions, or did anybody ever encounter such a problem. Many thanks. Eugene
