Kip 7170K Color scans have (5) distinct bands

[blackcat4866]

This was kind of long and drawn out, but I think I can condense it a little:

Another tech takes a call for poor quality color scans. It looks like this:
Color Scan Before.JPG

The original is just the standard shading chart, looks like this:
Shading Chart Original.JPG

We went out for a look, tried the shading adjustment (several times actually) and found that it failed after about 2 minutes, showing a red light on the scanner body. Reboot was necessary to restore scanner function.

As luck would have it Kip released bulletin 10800 the very next day describing this exact issue. There's an update kit and another calibration chart "Black Brightness". The kit includes two sets of springs for the shading rollers and some spacers for changing the focal length of CIS #2 and #4. There's also a firmware update that goes with it.

I wasn't available that day, but two of our best techs completed the updates and firmware, but the shading adjustment still failed in the same way.

Other failed attempts included replacing the shading roller mounts (most of which were broken at the snaps), re-seating the ribbon cables, and the scanner control board. No difference.

We heard from our Konica Minolta tech rep a few days later, recommending changing all (5) CIS. This is the result after the new CIS's, and replicating the CIS spacer bulletin:
Color Scan After_Before Calibration.JPG

This is what it looked like after initializing the BUD's, and completing the shading, stitching, and black brightness calibrations:
Color Scan After.JPG

When the shading adjustment was successful it took 3:25, and a screen popped up requesting that I scan the chart one more time which took only a few seconds. The stitching adjustment only took a few seconds. And it took (3) scans of the black brightness chart to get all non-red values.

In retrospect we could have skipped the replacement of the scanner control board. I though this might save somebody some hair-pulling. =^..^=