C451 shadow

[ES-OGT]

I have a C451 that's giving a very odd shadow. Basically it appears the print is continuing to smear but only as you get towards the edges (front and back of the paper path) of the page.

Here's the odd part, it only happens on LTR and LTR-R no matter the paper type. Legal and Ledger work wonderfully. I've attempted to replace the IU and made sure the fixes were in place to ensure a proper connection for developing. Below is a pic I took. The shadow unfortunately doesn't appear very well via scan or picture.

IMG-20130304-00027.jpg

[JustManuals]

Re: C451 shadow

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[Max]

Re: C451 shadow

looks like dev/drum passed its life or charge/grid covered in toner/dust.

[EarthKmTech]

Re: C451 shadow

does the machine have the plastic haircomb mylar installed on the metal plate above the transfer roller in the registration unit?

If the silver metal plate has nothing on it, this is an early machine and the bulletin for this issue has been ignored. Additionally, if the mylar is there, but the sharp points are worn off, its time to change it.

[Gaffers01]

Re: C451 shadow

You need to change the transfer roller, i have had this issue before.

[MAD0RAM]

Re: C451 shadow

You need to change the transfer roller, i have had this issue before.

X2

And it's an easy place to start.

[ES-OGT]

Re: C451 shadow

You need to change the transfer roller, i have had this issue before.

Would it still be the transfer roller even though the three colors look great? You can print something off with a mix of colors and black and the black will have problems and the colors look great.

[Mat Wilson]

Re: C451 shadow

Did the transfer roller fix your issues? I have had this fault on several machines and the transfer roller has fixed it every time.

[MAD0RAM]

Re: C451 shadow

Would it still be the transfer roller even though the three colors look great? You can print something off with a mix of colors and black and the black will have problems and the colors look great.

Yes.

[tech51]

Re: C451 shadow

Upping the second transfer levels fixes this problem with no need to replace parts. Look in transfer fine adjust and set black to 4 to start with. Gradually increase this value until the shadows disappear.....

[vladimir.mijatovic]

Re: C451 shadow

I got into EXACTLY this "shadow" problem with 3 different C451's on 2 separate occasions.
Both that I currently use have this issue and were getting me a bit pissed.
Both started doing these shadows - especially on BW pages.
One has a plastic haircomb mylar installed on the metal plate above the transfer roller in the registration unit, the other does not. So maybe this isn't the general solution for both that I use.
Tried some cleaning, but the problem remained.
(I must point out - I am not the type of guy to replace all important or/and expencive units by default if problem occurs)

Did some additional research over net...
And this nailed it on both machines. I put the Black value to 4 and it seems that the problem is solved.

Upping the second transfer levels fixes this problem with no need to replace parts. Look in transfer fine adjust and set black to 4 to start with. Gradually increase this value until the shadows disappear.....

If it sticks - "tech51" - you're the man! ;-)
Thank you!

[vladimir.mijatovic]

Re: C451 shadow

Well, the shadow returned :S
Second adjustment I made was:
"Solution ID TAUS0801599EN* Solution Usage 5Description
Black smudges/smears/halo-effect or text that looks bolded or offset on the second side.
Solution
CAUSE: The secondary transfer is set too low.
SOLUTION: To adjust the secondary transfer, perform the following:
1. Enter Tech Rep mode.
2. Select Image Processing Adjustment.
3. Select Transfer Output Fine Adjustment.
4. Select Secondary transfer Voltage.
5. Select Plain paper.
6. Select Black and increase the value to +7.
SPECIAL NOTE : Solution contribution by Mark D'Attilio, Production Print/SSD
"
seems to help, though it's still not 100% - so this topic is still open for sugestions.