Misfeed and misprint on first page, Riso FR3950UI

[cicr]

I’m experiencing a paper feed error on my Riso FR3950UI. Here’s the details:




The printer typically misfeeds on the first (sometimes second, if using card stock) page to print, resulting in a misprint. Vertical registration is off anywhere from 10mm (with standard paper) to 30-40mm (card). Ghost image visible on front and back of the second page, typically lasting until residual ink has been picked up off the pressure roller and drum (?).


Previously, the machine was misfeeding every third or fourth page (especially with card stock), sometimes jamming straight off (“Paper Misfeed Check paper feed area…” error message). If it was standard paper, the jam was occurring before the paper was pulled through the First Paper Feed Section. If it was card, it was either occurring at the same place, or once the paper reached the Second Paper Feed Section. Once it would print, vertical registration was inconsistent, and paper would often jam under the drum. The problem was always worse when using card stock. After making adjustments to the Elevator Upper Limit Sensor, Stripper Pad Pressure, and Timing Cam/Lever gap, the paper now feeds and prints, but always misfeeds and misprints on at least the first page.


I have the FR Series manual, downloaded from the Riso website, but the diagrams appear to represent the GR Series (it indicates a P Disc and Pressure Sensor Disc which, to my eyes, don’t exist on the exterior of the FR Series main shaft face plate).


Any ideas on what’s causing the initial misfeed/misprint? I’m under the impression that machine is malfunctioning somewhere in the Second Paper Feed Section or Press Section (likely the latter?).


For your viewing pleasure, I’ve included videos of the back of the machine and first paper feed section. I’ve also included an image of the ten prints on 175gsm card stock, with the first print on the left. The vertical alignment of the first print is off 24mm, the second is off 45mm, but the remaining eight prints are “Riso correct.” When printing on standard paper, the first misprint is less severe (around 10mm off) and all remaining prints are correct.


Thanks!





10prints.jpg

[DAG COPIERS & COMPUTERS]

I recently solved a problem of that nature by replacing the stripper pad on the stripper unit and adjusting the the dials on it to their correct positions. You could also experience that problem if the original which you scanned was not typed properly, by that i mean it does not have enough margin left on the leading edge. When i created a master with that original scanned with the leading edge turned the other way round, the machine stopped jamming papers immediately both under the drum cylinder and at the secondary feeding stage.
To be double sure, i repeated the 'experiment', this time by making another master but this time while putting the leading edge of the original the normal way, but shifting it slightly away from the top of the scanning glass, to ' increase' the vertical margin, then scanned. NO more PAPER Jam troubles.
Then I went back to the 'Reference point', scanned the original in the initial position it found was done in, i.e without allowing for ample margin on the leading edge, Paper starting jamming again!

Conclusion: Original was type without leaving or allowing for enough margin on the leading edge of the paper, the condition of the paper stripper not withstanding. That was my experience, yours could be different! It was a Riso FR3950U.