Konica MagiColor 2490MF Duplex Creased Jam

[NTL1991]

Hello everyone. While I'm not a printer/copier tech, I am a computer/networking one, so I hope it's okay that I post my question here among the pro's.

My trusty old MagiColor 2490MF is jamming while duplexing. I'll get an "Open Front Cover" Jam error, and after removing the drum unit, I'll inevitably find the duplex copy half printed on the second pass, with a 1/2" crease about 7" down the sheet. I can replicate the jam every single time, same output.

Any ideas where to start looking?

https://i.imgur.com/qhDvQtL.jpg
https://i.imgur.com/094sydt.jpg
https://i.imgur.com/5ybzhCK.jpg
https://i.imgur.com/NKf5x3j.jpg
https://i.imgur.com/LrrSj2P.jpg?

Nick