FS-602 Jamming when folding

[Guest]

We have an FS-602 (on bizhub 600) calling J-7224 and J-7226 when folding. First 2-3 pages ok but once first jam occurs pages begin creasing and jamming constantly. Looking like the folding stop plate is dropping to low position but not returning.

Have tested home position sensor, replaced folding rollings and stepping motor but no luck.

Can anyone help??

[Marsh2]

Try cleaning the exit sensor of the folding unit in the finisher i think this shouold work