C550 black shadow ? changed IU&belt

[sprawl]

Changed few times the Black IU and belt.

See attachments.

I'll try the "Initialize + Image Stabilization" and after that gradation adjustment.
Background voltages are -5.
Other settings are "0"(tcr, Dmax, etc...)

Any ideas ?

[edmund]

Need more info
Is there developer consumption taking place ?
Is there developer in the transfer belt cleaning unit ?
What is the IDC sensor reading sitting on ?

[sprawl]

Need more info
Is there developer consumption taking place ?
Is there developer in the transfer belt cleaning unit ?
What is the IDC sensor reading sitting on ?
------------------------------------------------

No there is no developer in cleaning unit. All seems like its ok.

When i do the gradation adjustment and other stuff the machine works few days and then its start again to do shadow.
Then i do again what i say in first post.

Sometimes its works few weeks, sometimes few days.
Machine are quite hard use, best result is 20000 copys in few days.



edit:
What is wrong IF THERE is developer in belt cleaning unit ?

[edmund]

answer to question
If there is developer in the transferbelt cleaning unit then the bias contacts on the mag-roller is faulty


The Black imaging unit could be expriencing faulty charging unit
please check the filter at the back of this tank

check the tank and see if the developer is not laying to one side in the tank

if I here of something else to fix this issue Iwill let you know

[emujo]

had the same issue recently on a C550, devloper was surging over the leveling blade and piling up on the back side of the I/U. This is not really serviceable, but I was able to remove filter and back side of drum pin to allow developer to be removed, and rotate magroller by hand to even out the sleeve. This worked for a few days but I had to replace the K I/U. Only about 40% of life on this unit. Not sure if there is a fix upcoming for this, but I have heard this is an issue.

[buster68]

this is a common problem with the C550. The IU is loosing contact on the back side because there isn't enough pressure on the blue lock lever in the front. You need to add about 3-4 mm shim to the black pads on the lock levers. This will secure the IU in place so it doesn't lose contact with the bias tabs. Then in service mode on the machine, select Image Process Adjustment, Transfer Output Fine adj, Secondary, Plain, Increase black to +7. Run stablizer.

[sprawl]

p-14

I putt a little peace of paper in black IU lockin system, black shadow is gone .

But if i print "Test Page" there is red lines center of "color patterns".
Code P14 is showing in the little mark of panel. If i print "Font list" its 100% fine. Only color pages have problems.

I clen the idc-censors and do gradation adj. again and other stuff butt is not working good...

Bacground voltages, dmax, primary adjustemts and other kind of that is set "0".

Image Process Adjustment, Transfer Output Fine adj, Secondary, Plain, Increase black to +7. Run stablizer.

I tested that option butt image quality is same.

[Bizwork]

The black shadow is based on a problem with the image unit and there will be a modification to the units to resolve the issue, as the doctor blade is the main problem, you may have to change the unit again .