Have two 5035's with DF71 finishers and print/scan systems. If you DUPLEX print or copy to the DF71 main tray, we never have a J60 code register and no duplex jamming. If you attempt to duplex to the inner tray of the copier in either copy or print mode, have duplex jamming within 3 copies of the run. This also occurs only, repeat only on 11 x 8.5 paper. Letter R and legal run fine. Units have just had 500K PM and new exit assemblies to help troubleshoot. Has been intermittent ongoing problem and I have also seen it on two other units not associated with these two. Have checked all pins in connectors for duplex and exit units. Can watch the paper stop, reverse toward duplex assy and then stop about 5 mm short of the duplex switch. Paper also hesitating about 5 inches past the AK70 attachment gates. Both units have all the latest and greatest firmware for main body and print system.

Hope this helps, duplex tray has 2 set of rollers with 1 spring in the middle. Stretch the springs about 2-3 mm. It will improve the feed and the timing.

Well, I guess there's a first time for everything. Invited the Kyocera Rep in to visit with this account and wouldn't you know it. Neither unit jammed the first time in over 450 duplexed copies in each machine. Ran 1/2 and 2/2 and stapled, punched and did a little dance on the floor, but no, absolutely no jams. The Kyo Rep saw the jam counts and took all the info, but what an experience. I think I need a long, long vacation. The Kyo Rep is now applying for Sainthood as he feels he waved his hands over the demented ones and drove the snakes out of Ireland. Go Figure.

I've also seen this type of jamming due to the spring coming off of this Bracket.

I keep a pair of the exit unit assemblies in Dan's picture on the shelf that I rebuild in the shop and take with me. The solenoids in this unit can go weak in less than a 100K. Just had a bad switch in a brand new exit unit also. I've seen the rollers on the duplex transport side get very slick, almost glazed. They need to be scrubbed with a 3M pad and alcohol or glass cleaner. I haven't actually replaced or the stretched the compression springs under the rollers as mentioned above but I carry a few of them just in case. Good luck with it and let us know what you found.