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sbillis
02-08-2009, 04:00 PM
Hello there,

I faced a problem when print on the C5500 KM with IC-408.
When we try to print a cmyk file on 200g or more thick paper, the characters that are black, appears blurred. (you must see the character with a magnify loupe). If we print a pure black (only K) file, character are ok.

When we print the same file on thin paper (80g,100g,150g) the characters are fine.
When we print at paper 100g that are register as thick paper (200g or 300g) the problem is appeared again.

If we print this file on C6500 with IC-408 no problem with character blur.

The engine is calibrated and we have tried to change toner density.

I believe that the problem is with the pressure of the 2nd transfer roller/Lw or with the 2nd transfer roller of cmy. Maybe some noise?
I try also to change this pressure to Auto, Normal or Low but nothing changed.
The service manual of C6500 writes something for dipsw 1-0 but am not sure if this is valid for C5500, because I change it an nothing happens.

does anyone faced this problem?
What are the main differents between C5500, and C6500 at the process section?

thanks

random
02-09-2009, 07:57 AM
Bad news. This is a problem on some machines and so far seems to be without resolve. If you have contact with KM direct I suggest you get on to them immediatly.

sbillis
02-09-2009, 12:30 PM
Bad news. This is a problem on some machines and so far seems to be without resolve. If you have contact with KM direct I suggest you get on to them immediatly.

do you mean some machines of c5500 or and another ones?

sbillis
02-15-2009, 09:14 PM
we have asked KM for this issue and they are investigating this.

We tried this trick, we replaced all the process unit (transfer belt,drums,coronas,imaging units and process carriage) from a KM c6500 and the problem has far away better. I can see that was dissapeared.

The process unit was new with very few prints. less than 500.

anyone has any opinion?

random
02-16-2009, 09:04 AM
This is the only way we have resolved this, also replace HV unit. Not a practicle fix for most people!!

sbillis
02-16-2009, 08:53 PM
This is the only way we have resolved this, also replace HV unit. Not a practicle fix for most people!!

you mean that you put in a new ones from c6500 and the hv unit?

random
02-17-2009, 07:17 AM
swapped the process unit from another machine and HV unit. Fault moved to the other machine.

sbillis
03-09-2009, 07:17 PM
here again...

We receive an answer from KM that told us to enable text thining, ISO coated, full output CGR etc from color expert setting, but nothing changed.

We swap process unit from c5500 to c6500 and vice versa and the problem appears now in both engines !!!
Same controller, calibrated etc.
:confused:
First, when we swap process unit from c6500 to c5500 and try to print without making auto gamma,color registration,calibration the result was good but still with some jitter-blurred character. After, we made auto gamma,color registration,printer gamma,calibration and ... problem appeared bigger !
:confused:
why do you think this is happen?
Remember, this happens when the file is cmyk on 250g or 300g paper. If file is only k on 250g or 300g paper, no problem.

maybe vibrations from 1st transfer rollers (colours) or high bias?
:confused:

random
03-10-2009, 09:05 AM
Well My theory is that the distance between the belt, front to rear is different. The gamma sensor is at the front of the belt and is unaware of the issue at the back of the belt (over toned) if the sensor was at the back maybe the text at the front would be lighter?

I would do a factory recall on both and run your setups again. Maybe one will come right.

redhotrob
07-25-2009, 12:54 AM
Anything new on this. I have a similar issue, excpet in addition the entire image is shifted about a half an inch from the lead to the trail edge.
I've rebuilt the process unit, exchanged the HV2 and ADU section with no success.

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