C6501 - 2.5mm image shift every 2nd sheet

**resolute** · 05-28-2010

I Have a very strange problem. Printing 13 x 19 Sheet - 10PT Carolina C2S Stock Coated GO 210-256gsm - every 2nd sheet the back to back registration is off by approx. 2.5mm. For example if I send down 10 sheets - autoduplex - Sheet 1 is good, sheet 2 is off, sheet 3 is good, sheet 4 is off -- and so on - It just affects every 2nd sheet. The strange part is that it is off by the exact same amount. Any suggestions?

**sbillis** · 05-28-2010

Restart Timing, Centering, FD, CD adjustments are made?
auto centering sensor enabled or disabled?

**resolute** · 05-28-2010

I have done the adjustments - even went through the entire tray alignment procedure.
How do I check regarding the Auto Centering Sensor?

**sbillis** · 05-28-2010

Originally Posted by resolute

I have done the adjustments - even went through the entire tray alignment procedure.
How do I check regarding the Auto Centering Sensor?

dipsw
26-4=0 for on =1 for off ADU
26-5=0 for on =1 for off LU,PF

maybe reverse for adu-pf

**sbillis** · 06-02-2010

do you have any news on this issue?

**HORSE** · 06-08-2010

I find that the Auto Centering tends to jump by 5mm.

Also it would be unusual to alternate good/bad/good/bad every 2nd sheet, I find that Auto centering tends to jump after maybe 30 or so sheets and then jump back after 20 or so sheets.

**Stirton.M** · 06-08-2010

I agree with Horse, turning off Auto center fixes the problem. After this, its a matter of adjusting the registration manually for all the trays. Can be a bit of a bear in the doing, but reliable. Use of image shift in the driver or CWS can tweak the minor deviancies.

This problem only shows itself on glossy stock, at least this is what I had noted. Bond or uncoated paper, the sensors work without fault.

Of course, the sensors can also be replaced.

The TSB information

Solution ID

TAUS0701183EN* Solution Usage 17

Description
Intermittent half-inch image shift on second side in the main scan direction.
Solution
PROBABLE CAUSES:
1. Failed Image Processing Board (IPB).
Verify failed Image Processing Board by swapping it with another board if possible. Replace the IPB as necessary (p/n A03U H020 28 for bizhub PRO
C6500/C5500 and p/n A0U0 H020 02 for bizhub PRO C6501/C5501 ).
2. Failed ADU centering sensor (PS65).

Replace the ADU centering sensor (p/n 56UA 8551 0E for bizhub PRO C6500/C5500 and p/n 56UA 8551 0E for bizhub PRO C6501/C5501 ).

**HORSE** · 06-08-2010

I would say that the problem is caused by the Black guide plates wearing 'Silver'

I have opened up both the PF & ADU units as of late for a physical observation and have noticed that beneath the area that the long centering sensor is located the black paint has worn away to reveal the silver of the metal showing through. Also as for the PF paper dust is another issue.