C550 light/faded print or copy

[ebm]

Aloha,

Any tech(s) out there experience intermittent light/faded printing on this model? Customer keeps calling for light images and has samples of the problem. However, there is no problem when the tech arrives on site. One sample the customer had seems to indicate the problem is isolated to black. Only the black print seemed to be faded or light, while the colored boxes and logos in the job were fine. Also, P-9 and P-21 alert codes appear on the management list.

Mahalo

[mikeena]

oh konicaminolta what have you done. i remeber when getting a new image unit ment it was new. but seriously i would take a look in replacing the image unit. i have seen this on a 550\350\450 basically evrey color machine that uses imageunits. they keep going out way to early. this issue is common for me. i have had it happen about 5 times in the last 30 days. i put in new image unit and about 1 to 2 weeks later im back there for quality issues

[laserman06]

P-9 is black image unit
P-21 is color registration failure(caused by the light black or P-9)

1. Question: Have you replaced the IU?
2. Cleaned IDC sensors?

Look in the service manual, page 600.

Also section 18 of the service manual has a good process to troubleshoot image quality issues.

I believe that it is most likely to be your black IU. Depending on the life counter Konica is warranting them.

[ebm]

Konichiwa

Tech has done the basics, IU,sensors,etc. We have claimed warranty on many IU's from Konica. Thanks for all the input.

Domo

[mikeena]

try replacing the transfer belt. we had a similar issue but instead of black it was all colors had a issue and black was fine. once we replaced the belt the problem went away

[ebm]

Hola,

Mucho appreciation for all who posted replies. Will try them all. We have a Konica DSM coming and I am sure he will tell us to do the same things that have been mentioned in this forum.

Gracias!

[B0265]

We had a brand new C451 with light copies and had to replace the transfer roller.

[Haroldbfix]

Im in C550 school this week, and the instructor has put alot of emphasis on doing the "Intialization and Stablization" adjustment. Then run the "Gradtaion" adjustments.

He seems to feel that this will reslove most CQ issues and related codes. Try it and see if this helps.

[mik]

hi,guys did anyone seen my post Bizhub c451-uneven top of the copy/printout
it is similar problem like on this c550,i changed all iu,cleaned all machine include idc sensors,ph unit,from inside.try with changing transfer belt and transfer roller and guess-nothing hapeend,the copy or prints is still much lighter on the top than the rest 3/4 copy?Please see post about bizhub-c451-uneven-top-copy-printout,there is much more about this problem.