C754 PRO strange problem

[copytrust]

Hello guys we have a c754 machine that has misaligment on black also this problem only occurs when the client is using thick paper, this problem was not new and when it happend i changed the black drum unit with a new one and the problem was fixed, now the black drum unit has made 30% of its life and started the same problem, the transfer belt does not have too many copies its on 50% of its life.
Does anyone have any other ideas?201905081309_0001.pdf

[suomi]

Re: C754 PRO strange problem

Developing unit?

[Synthohol]

Re: C754 PRO strange problem

black seems fine, its the cyan (possibly all 3 colors) that are askew.
print the same page in black only, the shadows will go away ill bet.

clean your registration windows, and do a skew reset.
[Service Mode] -> [Machine] -> [Print Head Skew Adj.] -> [Print Head Skew reset]

[copytrust]

Re: C754 PRO strange problem

black seems fine, its the cyan (possibly all 3 colors) that are askew.
print the same page in black only, the shadows will go away ill bet.

clean your registration windows, and do a skew reset.
[Service Mode] -> [Machine] -> [Print Head Skew Adj.] -> [Print Head Skew reset]

skew reset i forgot about that i am going to try that on my next visit! also i will check the colours maybe i made a mistake.

thanks.

[allan]

Re: C754 PRO strange problem

Looks like colour registration. Any warning codes Like P21 P31/33 or like that?

Also print a demo page the one with the bird and post that.

Does it go any after opening and closing the front door?

The (K)ey drum use an encoder to ensure surface speed. That encoder on the drive unit that can go faulty.

[copytrust]

Re: C754 PRO strange problem

Looks like colour registration. Any warning codes Like P21 P31/33 or like that?

Also print a demo page the one with the bird and post that.

Does it go any after opening and closing the front door?

The (K)ey drum use an encoder to ensure surface speed. That encoder on the drive unit that can go faulty.

There are no P codes on the machine. as i said it s only on thick paper mode on by pass and not always..
( closing the front door) i will ask the client to check it.
Encoder..... oh no please dont tell its like the drive unit the C451 had (what a nightmare that was) i ll check it on the parts catalog.

[tsbservice]

Re: C754 PRO strange problem

Agree with others, looks like color registration problem. If skew reset don't help you may try color reg. adjustment for thick paper.

[blackcat4866]

Re: C754 PRO strange problem

How thick paper? Within specs? Please don't guess. =^..^=

[tech51]

Re: C754 PRO strange problem

If it only happens on heavier stock, I would consider adjusting the fuser speed.

I had a c654e with similar issues a while ago and adjusting the speed cured it.

Might be worth a try.

[allan]

Re: C754 PRO strange problem

What i don't get is the overlay happens on the transfer belt. By the time the fuser get hold of it the image is already transferred to the paper.
If not in a warning state and not a physical problem , the engine firmware is the only other thing i can think of.
So could be a bad tweak under machine settings or can be corrected by tweaking.

IDCS dirty or faulty?

[kenpio]

Re: C754 PRO strange problem

Had one awhile ago that did this and it ended up being the transfer belt. There was a ding in the belt and the IDC sensors were not reading it right. I would get to the customer and it was not doing it, looks like it was printing in 3D.

KEN

[NexusTech]

Re: C754 PRO strange problem

IDC sensor is bad or dirty cannot reading

[copytrust]

Re: C754 PRO strange problem

I want to thank you all for your answers, i went yesterday to the client to perfom some tests, and to try some of your suggestions,
first of all as i said the problem does not occur every time, so here is what i have tried....
First i tried some 160grm papers in thick 2 mode by pass tray, after a few copies that problem appear, and then i tried with 80 grm in thick 2 mode
after a 10-20 copies that problem happend again, so i cleaned the IDCS, made a few copies again like 50, the problem didnt appear again.
so i think we are ok for now i ll wait for the client to test it further.

[bizhubPROricohPRO]

Re: C754 PRO strange problem

If machine before 500 000 total counter - IDCS, after 500/600 000 total counter probably dirty badge of Encoder.

[copytrust]

Re: C754 PRO strange problem

So i tried most of your suggestions, except the encoder, can you tell the location of the encoder? is it the same like the 451/452? cause in the parts catalog i can find it as a main drive unitmain.jpg