[Misc] Canon iR7105 Light partial image in halftone

[V-P]

Hi Everyone !

I have been reading some of the posts and I can see that there are some really Professional People here.

I am having a slight problem with a iR7105. Attached there is a scanned newspaper showing the problem.
This problem exists only in copying. Printing is fine.
So when you scan an image (halftone mode) to PC like the attached file, you can easily see what the problem is.
This problem happens the same if you scan from platen glass or DADF.

Already tried steps -

Cleaned:
the whole scanning system (lamp, mirrors, lens, etc)

Replaced:
Lamp
Inverter PCB
CCD unit
Reader controller PCB
Interface PCB

I have tried "Shading correction" procedure a few times.
The "white plate" is white.

I am out of ideas. I am pretty sure it must be a stupid thing, but I don't know what.

[charm5496]

are your internal prints fine?
when you are copying is it from the DADF or glass
Something isn't adding up here as everything that I am thinking of would affect copies and prints. DC controller possibly.

[teckat]

Stupid ? #1
did u clean the underside of the copy glass with ammonia free cleaner ???

does the light area patten stay the same ??
test for you_ Scan a solid black print of the glass and one thur the DF- post both of those image copies

[V-P]

to Charm5496:
It is the same result from DADF or Glass.
I forgot to mention but DC controller is recently changed to new version. (The one with extra chip to prevent halo image).

To Teckat:
Yes - glass is clean.
Yes - Pattern area is the same.

I am attaching both images - A4 size.
glass.jpgdadf.jpg

I am also attaching a printout from the machine and than I made copies using these modes:
TEXT Mode
Text - Photo
Printed Image

Here are the attached files. Maybe these can help

original.jpgprinted-image.jpgtext-photo.jpgtext.jpg

[teckat]

so where are the light streaks on these solid BLACK copies off the glass ???

[V-P]

On solid black, the issue is not visible.
I have attached some scanned copy samples of a printout.

Check the "text-image" and "printed-image" file.

You will see some kind of blur inside, round the light area.
Also "looks like" some scattering of toner inside the letters.

this is my main worry.

[teckat]

On solid black, the issue is not visible.
I have attached some scanned copy samples of a printout.

Check the "text-image" and "printed-image" file.

You will see some kind of blur inside, round the light area.
Also "looks like" some scattering of toner inside the letters.

this is my main worry.

now u are showing two different issues /
first u show a copy of a newspaper with light areas/

now u show Copies & a Print with toner blasting - u wrote Printed Image on it ????

when u say PRINT that means it is printed from a PC or Mac-[network] print out

a COPY is from DF or Glass-

so what is it Light Area issue or Toner blasting ??

[teckat]

inspect mirrors 1, 2 and 3 with a flashlight, look for a greenish or brownish film on any of the mirrors.
clean with a soft cloth, then alternating with alcohol and water a few times, the film should appear to be removed.
then adjusted the CCD's, LUT-ADJ1 and LUT-ADJ2.





did u clean The Laser Dust Proof Glass
7105Dust-proof.jpg
7105 Dust-proof.jpg

[V-P]

maybe my posts were a bit confusing.

So... the newspaper is just a newspaper which I put into the glass of the machine and I scanned it into a Windows based PC, saved as a jpg and uploaded here.
The idea was to show you that this quality image issue (in my opinion) is related ONLY to the scanning system or "Original Exposure System".
Even if I put the newspaper into the DADF, you would see the same image as the one I already uploaded.

The 3 images on the other hand:
It is just a config page printed from the machine. I uploaded the printed one (this is the one without any hand writing on it) to show you that the machine shows NO Quality problem in PRINT.

Than I put this page into the glass and made some copies using different modes for copying. You know when you disable Automatic Density on the copier display and there are some options like:
Text
text/photo
photo

So I made one copy for each mode and I wrote down on each page the corresponding mode.

I did this to show you that this quality issue is somehow enhanced or more visible when going from "Text" to "Photo". In other words when halftoning is involved.

I hope I made myself more clear now.

Thnx for reading

[gensys]

Search your problem only scaning system
Check Lamp> all mirror>lens>optic system>jampers>
In to laser system no problem, problem only scaning system.
Chek all.....

[V-P]

I know it is in the scanning system gensys.
Problem is where exactly.
Like they say : Location - location - location

I am going to follow Teckat advise on alternating water and alcohol and than will report again.

[V-P]

Ok - Result:

I closely (really closely with my glasses on) saw the mirrors (which previously I had cleaned just with soft lint free cloth).
I saw the greenish thing that Teckat said.
Cleaned a few times with alcohol and water + LUT1 & LUT2.
Scaning system is OK.

2 things:
1. Thank you Teckat !
2. I need to make an Eye-Check

[teckat]

Ok - Result:

I closely (really closely with my glasses on) saw the mirrors (which previously I had cleaned just with soft lint free cloth).
I saw the greenish thing that Teckat said.
Cleaned a few times with alcohol and water + LUT1 & LUT2.
Scaning system is OK.

2 things:
1. Thank you Teckat !
2. I need to make an Eye-Check

yeah'anytime
Z_Scott_The_Dude_Cartoon1.jpg