C451 black IU

[tech51]

Is anyone having problems with black IU`s on C451 dumping dev or internal dev contamination causing grey shadows. We`ve had quite a few just recently with this fault, Any ideas would be welcome.

[lucky13]

what does your gray shadows look like? are they at the ends of words with a tiny bit of the word lightly repeted ?does it happen with duplexed prints? here is a bullitian about the problem that helped me

[Bizhub]

The mod sheet should be fitted by now but if it is not get one and fit it. Also I think there is a quality issue with these black iu's as we have had several fail.

[tech51]

Its more of a cloud/smoky effect on the rear of the print. Its definately dev spill in the unit itself as you can some times clean it out, I was just wondering why it happens.

[minimerlin]

I have also see this problem...the cause is a mystery to me as the unit I pulled works in another machine!!

[big jase]

i have had the same problem, change unit with new one after 10 copies problem of shadow on copies, it turned out to be the coating on users paper, change the paper to mondi as KM recommend , problem went away after 20- 30 copies !! very strange but true!

[bigy]

I have the same problem. New black UI print maxim 45.000 - 130.000 A4, only color. I don_t print black works, to have no problems. With first Black UI I print aprox. 600.000. Now I have 1.150.000 with 451 - and constantly problems with black; I_m thinking to buy 6501.

[dudley]

I have also had trouble with the Black IU's. I have a feeling that the doctor blades are too high but thats just a guess. You pretty much have to split the dev unit off the IU and clean above and below the mag roller, and IF you haven't lost too much starter , you might get away with it. There was a mod for the bias contact on the rear of the IU but I have had both types dump. The C651 now has a separate dev and drum but I haven't seen one yet. Ihave shown tech support here the IU's but no real cure at this point

[bigy]

Thank you dudley,

It_s posible to put new black IU C651 to C451?

bigy

[Bizhub]

Thank you dudley,

It_s posible to put new black IU C651 to C451?

bigy

You can convert a C650 black IU to fit C451 but dont even think about fitting a C652 black IU as it is totally different it's more of a drum and dev unit set-up

[kesserling]

C 650

To day i remarque the similar problem with a C650 i change the Unit black and i have cloud in front of the copy (sorry for my english) and the same problem come after a moment i remarque a probleme in the transfert belt this one touch the unit black i corrige this problem and i do 500 copy and i think the problem its now behind me

[bigy]

hello bizhub,

thank you - but what it_s to made in the future?

my tech friend make something (unpack, clean, packing again) at the UI black - now I working with him, but I cannot print with black aprox. 1/2 of A4 paper. Everything from layout is black I fill with C=100; M=100; Y=100; K=0, and numbering from VDP software I make color. For clients maybe it_s not a problem, but for me is a lot of work - redesign all the files ....!

bigy

[CHACHA]

C451-550-650

The iu black is defect see attanchment

[kmcopier]

The unit is modified for this problemm you can add a small mylar for the distance between the magnetic roller and the drum

[tech51]

Hi KMcopier have you any more detail on the mylar mod,ie how thick and where it goes. Would appreciate it.