Ok ... maybe it's not unfixable. Maybe it just took me way too long to think of something.

Anybody who works on these series' of document feeders knows that on letter LEF originals you'll get a compressed section of image 82 1/2 mm from the trailing edge of the original, and a stretched section of the image 79 1/2 mm from the trailing edge of the original. It happens when the trail edge of the original is released from the registration roller and the original does a small shift front-to-back, like the original was dog-tracking just a little and straightened itself when released.

For one such customer who noticed, we tested every DF in our building, then swapped in the ONE document feeder that did not do it.

So Friday I came across it again, and got an idea. Supposing that the original WAS dog-tracking all along, and a previous tech tried to adjust out an original skew by swiveling the whole DF over the slit glass. Many techs do this, and it doesn't go well. The mylars at the slit glass exit no longer line up properly and snag the original corners, causing additional skewing and jamming.

So I aligned the DF on it's factory supplied alignment pins. Yes, it did original skew. Now there is an adjustment for simplex original skew in the top cover. When I did this adjustment the blurs disappeared, and the originals straightened out.

Original Skew Adjuster1.jpg

So if somebody tells you something is unfixable, take it with a grain of salt.