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blackcat4866
09-05-2018, 07:12 PM
Scans from the glass start scanning 32mm from the index plate. Leading edge is adjustable, but nowhere near that far.

Scans through the DF come out charcoal gray or black, because light source #1 is parked under the edge of the shading plate. Read position can be adjusted, just nowhere near enough to reach the correct scan position.

There are four occurrences of C9401, mainly because light source #1 was not properly aligned with the white plate at the time the shading adjustment was attempted.

The scanner finds home position each time after scanning, but then pulses out from that HP sensor too far. The scanner has not crashed yet, but I haven't tried scanning an 18" long original.

We've swapped the scanner home position sensor with an identical sensor from the same machine, and it does change state properly in test mode.
The scanner moves smoothly, lubricated rails, cables properly tensioned. Replaced scanner motor. Tried various timing belt tensions, no change. It's currently got the original belt tensioning spring.
Replaced scanner control board. Replaced MFP board. Updated firmware to G00-U8. Clipped wire ties in the scanner area.

For me, the really weird thing is that occasionally it will scan one document perfectly aligned.

Am I missing something obvious? =^..^=

tsbservice
09-05-2018, 11:19 PM
I would start reading theory of operation for that machine again. Seems you covered almost every avenue, so it could be something very simple. C9401 on 654/754e was CCD, but your issue is different.

driving lots of miles
09-05-2018, 11:23 PM
I am probably off base but has someone changed paper size/ scan settings? You seem to have covered everything else.

blackcat4866
09-06-2018, 12:10 AM
I am probably off base but has someone changed paper size/ scan settings? You seem to have covered everything else.

Explain. =^..^=

Woxner
09-06-2018, 03:18 AM
make sure the machine type is correct according to resolution. here is something else too


Check and clean the CCD sensor (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-cleanccd.PNG). Check and reseat connector CN3 on the CCD board (CCDB). Next, check the CCD cable and wiring for damage or loose connections. Reconnect or repair as needed. Test MFP operation. If any issue is found. Replace the CCD unit. (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-ccd-replace.PNG)
CAUTION: When the CCD is replaced, perform the following adjustments.

[Service Mode] -> [System 2] -> [CCD Calibration (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-CCDcalib.PNG)] = [OFF]

[Service Mode] -> [System 2] -> [Line Mag Setting (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-linemagsetting.PNG)] = [OFF]

[Service Mode] -> [Machine] -> [Scan Area] -> [Main Scan Zoom Adj. (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-mainscanzoom.PNG)]

Note: If the specifications are not met, loosen the CCD board mounting screws and move the CCD board in the sub scan direction as necessary. Hold the CCD board by hand when moving it. NEVER use a screwdriver or similar tool to tap to move it, as a varied distance between the CCD sensor and lens results.

[Service Mode] -> [Machine] -> [Scan Area] -> [Scanner Image Side Edge (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-scannerimageside.PNG)]
[Service Mode] -> [Machine] -> [Printer Area] -> [Image Position: Leading Edge (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-imageposition.PNG)]
If error persists, continue troubleshooting.

Please refer to Board locations, connectors and wiring (http://cscsupportftp.mykonicaminolta.com/media/7_8_series/808-c9401.PNG).

IMPORTANT: Please check the wiring harness(es) by unplugging all associated connectors, checking all wires to ground (for a short) and checking continuity of the wiring (for an open).

blackcat4866
09-06-2018, 04:41 PM
Well the CCD is about the last thing left in the scanner not changed. I have a hard time seeing how it would affect light source#1 position though.

All the scanner connectors have been examined and reseated multiple times. Thanks for your response. =^..^=

driving lots of miles
09-06-2018, 07:57 PM
Explain. =^..^=
I was thinking that if settings had been changed it could be throwing off the position of the scanner. We had a copier that was not copying the entire page or parts of it and the page and tray paper settings had been changed. The internal prints were coming out perfect, it was just the scans and copies.

blackcat4866
09-06-2018, 09:29 PM
I was thinking that if settings had been changed it could be throwing off the position of the scanner. We had a copier that was not copying the entire page or parts of it and the page and tray paper settings had been changed. The internal prints were coming out perfect, it was just the scans and copies.

I'm not ready to discount your idea yet, but what sort of setting might the customer change that would affect the light source #1 scan position under the slit glass? =^..^=

driving lots of miles
09-06-2018, 10:36 PM
I'm not ready to discount your idea yet, but what sort of setting might the customer change that would affect the light source #1 scan position under the slit glass? =^..^=

There should not be anything the customer could do that would affect the light source, this is a really an odd problem.

blackcat4866
04-03-2019, 11:29 PM
Correction: I just got this from the team leader: The second new CCD fixed it. The first new CCD did not change the symptoms. =^..^=

Madnhain
04-11-2019, 02:02 PM
I posted this in the other thread related to this on my 2 808s... make sure you check the screw on the scanner drive gear on the back right of the machine accessible by removing the top right cover. there is a screw that secures the gear to the metal drive shaft. This screw comes loose and is too short from factory. Replace this screw with a longer and it resolved our scanning issues with identical symptoms.

KM will be releasing a bulletin on this directly.

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