C6500 - color density problem

[zmeutz]

Hi!

I have a konica minolta c6500 problem...
color density of printing are very low

transfer belt it’s new, corona’s changed...

inservice mode, I set auto gamma adj. and color registration...
no change...

I stopped it to see color density on transfer belt
in test mode i put +125 and it’s very low and at +255 it’s near but not enough

I attached some pictures maybe someone can help me and point me to the right direction

thanks!
stefan

[Toxic]

You should mention more details like meter count, developer and drum count, toner used (OEM or some replacement)...
Is problem just magenta or all colors?

[Synthohol]

one color or all colors?
if you suspect one color, tape up the DV inlet hole and swap DV units/drums around and see if the problem stays with the DV unit or the color slot.
alway leave the toner door open when testing this so it wont try to add toner.

[zmeutz]

You should mention more details like meter count, developer and drum count, toner used (OEM or some replacement)...
Is problem just magenta or all colors?

developer units are all changed, they have around 5000 listed pages
drums have ~ 10000 pages ...
toner oem

it makes on all colors ...




one color or all colors?
if you suspect one color, tape up the DV inlet hole and swap DV units/drums around and see if the problem stays with the DV unit or the color slot.
always leave the toner door open when testing this so it wont try to add toner.

there are all colors

I'm not sure but I think this problem starts after a deep cleaning ...
also replace corona's and transfer belt ...

I checked again all contacts and rollers ... to be smooth area to all contacts ... CMY on left of transfer belt chassis and black with 2th transfer roll to the right of transfer belt ...

also cleaned transfer roll from front of fusing unit ... checked again to be smooth area in front of machine ...


on transfer belt, I stopped in the middle of transfer on the belt, and I saw large amount of toner on transfer belt, after separation, half on the page and half on the belt ...

[Toxic]

Then it must be some problem with 2nd transfer process.
Did you put back 2nd transfer roller corectly?
Also check earth plate on lower transfer roller (before fusing unit).
Did this problem occur after service or was there before replacing parts?

[Synthohol]

Yes, make sure the wire is plugged in good for the 2nd TX assy

[zmeutz]

Then it must be some problem with 2nd transfer process.
Did you put back 2nd transfer roller corectly?
Also check earth plate on lower transfer roller (before fusing unit).
Did this problem occur after service or was there before replacing parts?

I say that it's correctly ... smooth area inside the printer... where is a screw and connector with plastic piece that touch the roll

Earth I checked 5 time till now, and again now ... I made also some pictures with position of the roll

I didn't checked before because it was full of toner inside and transfer belt was damaged


Yes, make sure the wire is plugged in good for the 2nd TX assy

You say about 2nd transfer roller before fusing unit?


https://i.ibb.co/GCkDWTz/IMG-0012.jpg (https://ibb.co/GCkDWTz) https://i.ibb.co/Mc6MvMQ/IMG-0013.jpg (https://ibb.co/Mc6MvMQ) https://i.ibb.co/vqpR2kY/IMG-0014.jpg (https://ibb.co/vqpR2kY)

L.E.

I think I solved it ... I don't know how I saw it ... but I saw ...
Inside of the machine, the connector for 2nd assy was damaged ...

https://i.ibb.co/7JR4J56/IMG-0016.jpg (https://ibb.co/7JR4J56)

[Toxic]

You say about 2nd transfer roller before fusing unit?




I think Synthohol mean connector for discharging assy, right after lower transfer roller.
I would check 2nd transfer roller pressure mechanism, pressure release motor, cam, pressure arm...
Try to change pressure and see is there some difference in transfer.

Edit:you edited last post so i have too, that broken connector definitely could be the problem :)

[zmeutz]

I think Synthohol mean connector for discharging assy, right after lower transfer roller.
I would check 2nd transfer roller pressure mechanism, pressure release motor, cam, pressure arm...
Try to change pressure and see is there some difference in transfer.

Edit:you edited last post so i have too, that broken connector definitely could be the problem :)


problem not solved ... still persist ...

I will try to check transfer belt, 2nd transfer roller pressure mechanism,
pressure release motor(can I check from service menu if it turn on or off?)
cam?
pressure arm? :(

[Toxic]

If you dont have SM i suggest you find it, if you want to do something on this machine.
Some things is hard to explain, lot easier with SM and theory of operation.
How did you resolve that broken connector?
Transfer pressure bellow from SM
50433

[zmeutz]

If you dont have SM i suggest you find it, if you want to do something on this machine.
Some things is hard to explain, lot easier with SM and theory of operation.
How did you resolve that broken connector?
Transfer pressure bellow from SM
50433

sorry, I was thinking that you talk about, transfer belt assy ...
that's why I asked about cam...

I have SM and I saw cam at 2nd transfer unit, before fusing unit ...

I will give a try again tomorrow ..

Thanks for help!
I will return with news...

[zmeutz]

If you dont have SM i suggest you find it, if you want to do something on this machine.
Some things is hard to explain, lot easier with SM and theory of operation.
How did you resolve that broken connector?
Transfer pressure bellow from SM
50433

I inserted a screwdriver inside the spring and I move it a little bit ... it comes by himself in the right position...

2nd transfer roller pressure mechanism - tested with door opened ... works it came up and back down ... but still large amount of toner remain on transfer belt ...
pressure release motor - tested works ..
cam - in the right position
pressure arm - in the right position

I saw counter of roll and it has 224.000 prints (I saw it was used only in A4S ... because I see wear in the middle but on A3 it's the same ...)

I will try to replace both of them, TB one and this one ... because prints on all colors are very low density

I attached this image, it must to be deep orange ... but isn't :(
https://i.ibb.co/mh977sD/IMG-0022.jpg (https://ibb.co/mh977sD)

I see on transfer belt consistent amount of toner, but only small amount remain on page

[Toxic]

You could try change this settings and see is it make some difference but i am more on the hardware side problem


Change Dipswitch 1-0 (To display process adjustment to user screen) from 0 (Default) to 1.
Then, [Process adjustment] key is accessible from COPY (or MACHINE) screen.
(COPY (MACHINE) => [Paper Setting] => [Change] => [Process Adj.] => [2nd transfer Offset (Front) and/or (Back)])
Set appropriate 2nd transfer current for each tray referring paper being used. However, when too high or too low value is entered, the adjustment fails.

[zmeutz]

You could try change this settings and see is it make some difference but i am more on the hardware side problem


Change Dipswitch 1-0 (To display process adjustment to user screen) from 0 (Default) to 1.
Then, [Process adjustment] key is accessible from COPY (or MACHINE) screen.
(COPY (MACHINE) => [Paper Setting] => [Change] => [Process Adj.] => [2nd transfer Offset (Front) and/or (Back)])
Set appropriate 2nd transfer current for each tray referring paper being used. However, when too high or too low value is entered, the adjustment fails.


I will test it later ... but till then I already ordered connectors for both transfer rolls, I think maybe from there is the problem ...
A friends guide me, if the black connector from transfer belt it's damaged (see picture) then it loose voltage and can be from there doesn't work good transfer ...

https://i.ibb.co/mqHsxp3/DWCB1063.jpg (https://ibb.co/mqHsxp3) https://i.ibb.co/TcRPNGV/JNOS3351.jpg (https://ibb.co/TcRPNGV)

[tulintron]

Run Factory Default under Recall Standard Data under Process Adjustment.


Then run test pattern N. 80 and compare the colors


Do not let the printer adjust. Run the test right after the Factory Default.

[Toxic]

Tulintron, good point , i totally forgot about that step.

[zmeutz]

Run Factory Default under Recall Standard Data under Process Adjustment.


Then run test pattern N. 80 and compare the colors


Do not let the printer adjust. Run the test right after the Factory Default.


https://i.ibb.co/D5286yt/IMG-0029.jpg (https://ibb.co/D5286yt)

colorful ...
very nice colors ... :D

after gamma adjustment and color registration
https://i.ibb.co/0qdjZMT/IMG-0030.jpg (https://ibb.co/0qdjZMT)

[zmeutz]

I start to think that the problem starts from gamma sensor,
when I cleaned boards from gamma and color registration sensor can be that I touch this 2 adjustments...
https://i.ibb.co/Fgsyb0N/77955-E34-205-C-43-A2-9956-CE3-CEC6136-BC.jpg (https://ibb.co/Fgsyb0N)

can I find right position of them, or can I readjust them?

thanks!

[methogod]

replace, if cleaning didn't fix. Usually overcompensates the other way when dirty.

how many test prints did you run before it go lighter, before adjustment? i would have ran a bunch just to be sure it didn't lose density on it own.

[tulintron]

https://i.ibb.co/D5286yt/IMG-0029.jpg (https://ibb.co/D5286yt)

colorful ...
very nice colors ... :D

after gamma adjustment and color registration
https://i.ibb.co/0qdjZMT/IMG-0030.jpg (https://ibb.co/0qdjZMT)
Changing would be the best alternative. However, in the printed tests, it seems to me to have a developer with a shelf life at the end.


Cyan prints bad colors.


The yellow background after the adjustments is a faulty gamma sensor characteristic.


But be sure to change the developers if necessary.


This sensor strip has an update. Pay attention when making a purchase.

[zmeutz]

Finally solved, I replaced registration frame assy

I think gamma sensor it’s damaged

Thanks for help!