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stevena86
01-31-2014, 06:17 PM
Hello there,

Been finding answers to a lot of copier issues I've had in the past on this site, but unfortunately couldn't find an answer on here already asked and solved that would help me with the problem I am having now.

Have a customer that has a Bizhub C353 that when printing images it has on it thousands of little white spots, making the image look gritty and of poor-quality. When running gradation and half-tone patterns, you can visibly see white spots in the fill. When doing an emergency stop during the printing process of a Yellow half-tone pattern, you can see the dots on the transfer belt as void areas. I have replaced the K IU, Transfer Belt, Ozone Filter and Secondary Transfer Roller already.

My question is: Could this be laser unit related (to where the problem exists in each separate laser unit) or a voltage problem?

Before on this machine, the clutch in the Feed/Transport Drive Unit had worn out the bushing in the unit and caused a loud noise followed by blank prints of Black only. After replacing the drive pack and clutch, the machine ran fine for over 3 months until now.

I've attached a few images of the problem that I am having.

Any help is greatly appreciated!

23762 23763 23764

JustManuals
02-01-2014, 12:59 AM
This Parts & Service Manual can now be purchased for $12.77 and downloaded immediately after payment from:


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Paul@justmanuals.com

AjitN
02-01-2014, 04:35 AM
Looks like Bad Toner OR poor transfer ( 1st or 2nd) OR paper quality.
Check image on drum, if problem exists it may be developer or toner.
try another paper or print same image for two sided, if second side image is good its paper problem.
Try replacing belt assy.
Hope this help

stevena86
02-01-2014, 05:01 AM
Thanks for the reply.

Sadly I do not believe it to be a paper issue as you can see the dots in the transfer belt before it's even gotten to secondary transfer. I've replaced the transfer section (primary and secondary) and the problem persisted.

Dougtech
02-01-2014, 05:48 AM
question - did you run gradation pattern of each color and did it appear in each color or possibly only one color?
How many copies are on your C353?
Is your eye loop photo of a true black page or a composite black page?

Wondering as these may help track the problem down.

fishleg
02-01-2014, 09:16 AM
Transfer belt 100% only seen it once but new belt fixed it.

Sent from my Nexus 7 using Tapatalk

stevena86
02-01-2014, 09:18 AM
question - did you run gradation pattern of each color and did it appear in each color or possibly only one color?
How many copies are on your C353?
Is your eye loop photo of a true black page or a composite black page?

Wondering as these may help track the problem down.


Yes, I ran the gradation for each color in Service Mode -> Test Mode -> ran Gradation pattern and Half-tone pattern tests and the problem exists in all colors. I used the eye loop to illustrate it better so you could see the problem, and used Black as it was the easiest to see in the picture which was a true black and not a composite black page, but when running Yellow and stopping the print process while the image is still on the transfer belt you can see the void areas in the image.

stevena86
02-01-2014, 09:20 AM
Transfer belt 100% only seen it once but new belt fixed it.

Sent from my Nexus 7 using Tapatalk


Have already replaced with a brand new, never opened one and the problem persisted. Have a hard time believing I had the problem before replacing and got a bad transfer belt with the exact same issue.

Synaux
02-01-2014, 10:16 AM
Have already replaced with a brand new, never opened one and the problem persisted. Have a hard time believing I had the problem before replacing and got a bad transfer belt with the exact same issue. Image Process Adjust...etc Its a new belt, but is it running dirty? Try increasing the Primary Transfer Adjustment / Media Adjustment.... State confirmation values within spec? Level 1 History Dev Bias Choice Reset Firmware PH Unit Hopper Unit Boreds///

copier tech
02-01-2014, 10:57 AM
Synax has the best answer, first step get the latest firmware on the machine.

If you do gradation test prints full bleed does the fault occur on all colours or just black?

stevena86
02-04-2014, 02:23 AM
After doing what was listed here:

Replacing the image transfer belt
Replacing the secondary image transfer roller
Increasing the Primary Transfer Voltage
Rewriting the firmware with G00-R6
Cleaning the LSU glass on all 4 LSU's
Testing the voltage from the HVPWB

It came down to the paper the customer was using. Took a ream of 28lb Hammermill copy paper with me today and after doing all the things listed above, I ran the better quality paper just to say I did it and low-and-behold the issue did not show up on the higher quality paper. Only conclusion I could come up with is that there is something wrong with the paper the customer was using.

Blew my mind. But thanks for all the help from you all. Was greatly appreciated. Feel free to mark this solved.

Synaux
02-04-2014, 05:22 AM
After doing what was listed here:

Replacing the image transfer belt
Replacing the secondary image transfer roller
Increasing the Primary Transfer Voltage
Rewriting the firmware with G00-R6
Cleaning the LSU glass on all 4 LSU's
Testing the voltage from the HVPWB

It came down to the paper the customer was using. Took a ream of 28lb Hammermill copy paper with me today and after doing all the things listed above, I ran the better quality paper just to say I did it and low-and-behold the issue did not show up on the higher quality paper. Only conclusion I could come up with is that there is something wrong with the paper the customer was using.

Blew my mind. But thanks for all the help from you all. Was greatly appreciated. Feel free to mark this solved.

Sometimes it's the simple things...do they know how to fan the paper? Sometimes you have to train them like monkeys.
Glad to see you got it working!

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