Timing delay on duplex MP C7500

[CSI]

Hello,

On a MP C7500 I have a timing problem duplex only on A4 pad of about 8-12 mm over about 40% of the copies (print or copy).
No problem A4R or A3 or A3 +. Only A4

The machine causes no jam, just an offset printing on the reverse.

If I change my loop frame, there is a jam. So the original setting is good.

I disassembled everything, duplex, synchro cell but nothing better!

Have you any idea?

[NeoMatrix]

You might like to check :
User tool|system settings| edit |2 side auto margin
T to T = 0 and T to B = 0 ( Both set to Zero margin)

HTH

[CSI]

That's not a problem of User tool|system settings because 40% of the pages are criminalized

[slimslob]

I have not worked on this model so I can only make general observations. With the problem occurring on both copies and printing, the document feeder is not the problem as it is not involved with printing. I believe that the reverse side is printed second. The problem has to be some kind of drag on the paper transport rollers. Check rollers that the A3 paper would still be in when it leaves the registration point that shorter paper sizes are not.

[NeoMatrix]

I don't work on this model either. Something to try.
Check separation feed clutch is having correct resistance else you may have a second sheet advanced in the feed path which may give you advanced paper feed/buckle at the rego-roller.

You have a timing issue...