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B0265
06-28-2023, 03:20 PM
We are struggling with a C250i and I'm hoping someone have any suggestion.
There is only yellow toner on about 6 cm in the front side fading from front to rear. Also you can no see the steps on the gradation prints like you can se on C,M and K.
The plack prints are a bit grainy but I don't know if this is related to the Y problem.
So far we have replaced Y drum, Y developing unit, transfer belt, high voltage board, PH unit, base board, and EXCB.
The total counter is 48000, OEM toner and the machine is clean inside.

Cantechman
06-28-2023, 03:35 PM
C250i No yellow on rear side of page


We are struggling with a C250i and I'm hoping someone have any suggestion.
There is only yellow toner on about 6 cm in the front side fading from front to rear. Also you can no see the steps on the gradation prints like you can se on C,M and K.
The plack prints are a bit grainy but I don't know if this is related to the Y problem.
So far we have replaced Y drum, Y developing unit, transfer belt, high voltage board, PH unit, base board, and EXCB.
The total counter is 48000, OEM toner and the machine is clean inside.


Have you tested the toner supply motor for yellow?

Synthohol
06-28-2023, 03:50 PM
was the laser glass cleaned with the wand?
did this happen before or after some type of service?

B0265
06-28-2023, 04:24 PM
was the laser glass cleaned with the wand?
did this happen before or after some type of service?

We have replaced the PH unit twice (two different units).

B0265
06-28-2023, 04:36 PM
Have you tested the toner supply motor for yellow?
No but the problem remains right after replacing the developing unit, did first test with a unit from another C250i then with a new unit.
The TCR value is a around 7 so I think the toner supply works.

allan
06-28-2023, 05:28 PM
Did you convert a K unit drum or developer to Y? The mag roller is not camming up to the drum on the one side.
If you use anything but correct DV or DR there are some mods to be done.

Or something is seriously obstructing the laser path.

tsbservice
06-28-2023, 07:21 PM
I would Remove DV unit and check mag brush. If there is even brush then I would stop machine midcopy solid yellow pattern and check the drum etc. You need to isolate the problem a bit I think.

copier tech
06-28-2023, 09:25 PM
We are struggling with a C250i and I'm hoping someone have any suggestion.
There is only yellow toner on about 6 cm in the front side fading from front to rear. Also you can no see the steps on the gradation prints like you can se on C,M and K.
The plack prints are a bit grainy but I don't know if this is related to the Y problem.
So far we have replaced Y drum, Y developing unit, transfer belt, high voltage board, PH unit, base board, and EXCB.
The total counter is 48000, OEM toner and the machine is clean inside.


Is the yellow drum & DV unit racked into contact with each other correctly? Looks like they not racked in evenly, check the rear locking arm etc.

B0265
06-29-2023, 08:58 AM
Did you convert a K unit drum or developer to Y? The mag roller is not camming up to the drum on the one side.
If you use anything but correct DV or DR there are some mods to be done.

Or something is seriously obstructing the laser path.

No converted units, the problem started with the factory installed units and we have only used OEM parts during the trouble shooting.
It looks like something might obstruct the laser path but I can't see what that might be.
Since we have tried with two other PH units it's not in the unit or on the slit glass.

B0265
06-29-2023, 09:04 AM
I would Remove DV unit and check mag brush. If there is even brush then I would stop machine midcopy solid yellow pattern and check the drum etc. You need to isolate the problem a bit I think.
The coating on the developing roller looks fine, it's even all over the surface.
I have never stopped the machine during printing and tried to pull out a color drum when the 1st transfer roller is in the down position, can this be done without any damage?

B0265
06-29-2023, 09:09 AM
Is the yellow drum & DV unit racked into contact with each other correctly? Looks like they not racked in evenly, check the rear locking arm etc.
It's difficult to see if the drum and dev units are in contact in the rear side but the dev unit release arm looks fine as far as we can see.

tsbservice
06-29-2023, 11:47 AM
The coating on the developing roller looks fine, it's even all over the surface.
I have never stopped the machine during printing and tried to pull out a color drum when the 1st transfer roller is in the down position, can this be done without any damage?
Yes drum can be pulled.

Gift
06-29-2023, 01:20 PM
Haven't read the whole story here but did you try and interrupt the print process (open cover during printing) and check the image on the drum/itb surface?

B0265
06-29-2023, 02:10 PM
Haven't read the whole story here but did you try and interrupt the print process (open cover during printing) and check the image on the drum/itb surface?
Not me personally but P8 & P21 is shown all the time so I'm pretty sure the yellow image is missing on the transfer belt.

allan
06-29-2023, 05:36 PM
Could also be a broke part on the TBU that press the primary transfer roller down. So hope stopping the machine and pulling the drum could help a bunch.
You did mention changing the TBU.

Under service mode try to adj the primary transfer current to both extents and see if it will do more or less than that 6cm. Its not to far fetched to be a HV current leakage.

Gift
06-30-2023, 09:36 AM
Not me personally but P8 & P21 is shown all the time so I'm pretty sure the yellow image is missing on the transfer belt.

Well I think checking with your own eyes is better than believing, especially if it's not a big effort to take a look. If the toner-image is fully there on the drum surface but only partially transfered on the belt you probably have an issue with it's inner parts (yellow 1st transfer roller).

Toxic
06-30-2023, 10:09 AM
Did you try to mark developing roller position and check after print does it moved?

tulintron
06-30-2023, 10:57 PM
You can do a test on an A3 or 11x17 sheet, with 100% coverage in yellow and during the process of transferring the drum to the ITB, you open the front cover to stop the process. At this moment, analyze the drum and the ITB

Woxner
07-01-2023, 12:56 AM
my two cents is the itb roller is not sitting down on drum. i have seen these break and do this

Brad6784
07-01-2023, 04:33 PM
my two cents is the itb roller is not sitting down on drum. i have seen these break and do this

Do you mean primary roller? The OP said he changed the yellow drum and transfer belt, which kind of rules that out. I think this needs more investigation, stopping mid print on an A3 255 half tone test would be a good start.

Id be interested to hear what cures this issue!


Sent from my iPhone using Tapatalk

allan
07-01-2023, 05:07 PM
Be lazy and see if you are creating yellow waste. If so its the TBU if not the drum or it is to far from the mag roller on one end else HV. Can win a prize for grammar with that. Its not the laser in my opinion looks like static.

B0265
07-05-2023, 03:24 PM
I think we have found the cause. The rear rib that put pressure on the developing unit look normal from the outside but when we did put some pressure on it we found that it's not fixed to the shaft so the plastic is probabaly broken. Now we must figure out how to get to this part and if it's possible to fix it. These parts are not listed in the parts guide manual.

Cantechman
07-05-2023, 08:29 PM
I think we have found the cause. The rear rib that put pressure on the developing unit look normal from the outside but when we did put some pressure on it we found that it's not fixed to the shaft so the plastic is probabaly broken. Now we must figure out how to get to this part and if it's possible to fix it. These parts are not listed in the parts guide manual.


Do you have a picture of where that part is? it would be good to know for future reference.

copier tech
07-05-2023, 09:55 PM
I think we have found the cause. The rear rib that put pressure on the developing unit look normal from the outside but when we did put some pressure on it we found that it's not fixed to the shaft so the plastic is probabaly broken. Now we must figure out how to get to this part and if it's possible to fix it. These parts are not listed in the parts guide manual.


You're welcome .............. :rolleyes:

B0265
07-06-2023, 08:11 AM
Do you have a picture of where that part is? it would be good to know for future reference.
No picture, but if you remove the drum and dev unit and turn the release lever you can see the white ribs that put spressure on the dev unit.

avecosat
09-22-2023, 01:25 PM
No picture, but if you remove the drum and dev unit and turn the release lever you can see the white ribs that put spressure on the dev unit.
Hello, was the problem solved with this solution?

B0265
09-26-2023, 01:30 PM
Hello, was the problem solved with this solution?
No we have not repaired it yet. We will try to find out if the parts from a C258 can be used.

joeywatt
10-17-2023, 06:52 AM
Hello. I'm having the same issues with you. Can I ask if there is a solution? Website (https://countertopinstallationtampafl.com/) Website (https://www.tampastuccorepair.com/)

Mildred
10-17-2023, 08:05 AM
I had an issue the other day when changing a drum.

When I released the pressure of the developer I lost magenta on the rear side of the page. Just like your yellow.
I stopped the print and checked image on the drum and transfer belt. Found it was not transferring developer from developer to drum.
My TCR levels were correct around 6 to 7.

What I found was the developer ! Just above the developer roller there is a black cover that goes the length of the developer roller. It slides in and clips into place. From a quick glance it looks in place but is loose and held in by tape if I recall. Not properly clipped in. When this guide is out of position it alters the developer to drum spacing causing faint prints front to rear.

I have attached a picture of a developer with a arrow pointing to the guide I am referring.

Hope this helps, if it the same as my issue I had.

regards

sylvain alp
10-17-2023, 08:26 AM
have you checked the patches on the belt and check if there are any P. messages?

have you checked the patches on the belt and check if there are any P. messages?

tsbservice
10-17-2023, 08:43 AM
I had an issue the other day when changing a drum.

When I released the pressure of the developer I lost magenta on the rear side of the page. Just like your yellow.
I stopped the print and checked image on the drum and transfer belt. Found it was not transferring developer from developer to drum.
My TCR levels were correct around 6 to 7.

What I found was the developer ! Just above the developer roller there is a black cover that goes the length of the developer roller. It slides in and clips into place. From a quick glance it looks in place but is loose and held in by tape if I recall. Not properly clipped in. When this guide is out of position it alters the developer to drum spacing causing faint prints front to rear.

I have attached a picture of a developer with a arrow pointing to the guide I am referring.

Hope this helps, if it the same as my issue I had.

regards

This is very interesting, thanks for heads up Mildred!

joeywatt
01-25-2024, 06:54 AM
I think you should check the patches. That worked for me too. safety pool fence (https://poolsafetyfencejacksonville.com/) pool fence (https://www.premierpoolfenceorlando.com/)

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