HP Designjet 4500 Scanner - thin white vertical line about at the right stitch wire

[pbrooks259]

Hi, on an HP Designjet 4500 Scanner I get a thin white vertical line at about the location of the right stitch wire. White line is Full length. It is set on "photo".

I have tried cleaning the white background, the glass, and underneath the glass.

I don't see a scratch on either the glass or white background in the vicinity of the white vertical line.

I don't see a dust speck in that vicinity.

I have calibrated several times deleting the parameter blocks a few times as well.

The calibration sheet is beat up a bit but not real bad, not dog-eared, but it is used. It does have a little bit of dark roller marks.

I've got to get rid of this white line. Not sure what to do presently.

(I have noticed the roller marks on the calibration sheet appear to come thru on the scans as well. I have gotten rid of that some with a background cleaning setting of 10.)

I confess on the recommendation of another scanner user I have used a "daylight" fluorescent lamp instead of the OEM lamp. This has worked OK on other 4500s.

Maybe I should go back to the OEM lamp which has about 4200 hours on it.

Maybe this is caused by the non-OEM lamp; I don't know.

Thanks for any input whatsoever.

Paul

[pbrooks259]

....I notice that the calibration sheet has a small thin black vertical line in the white block of the calibration sheet in the same vicinity as the resulting thin white vertical line in the resulting scan.

But I don't know whether there is cause and effect. I will put a white sticker over it and see if there is any change. There is probably no cause and effect.

[Lance15]

It would make sense that it would.......

If there is contamination (whiteout, ink, dust, etc) on the glass, you'll get a black line when scanning.

If there is contamination on the document, you should get a white (dropout) line.

I think I'm thinking about that right.

[Phil B.]

It would make sense that it would.......

If there is contamination (whiteout, ink, dust, etc) on the glass, you'll get a black line when scanning.

If there is contamination on the document, you should get a white (dropout) line.

I think I'm thinking about that right.

Lance,

That is the theory the way I understand it also!

good call Brother!

[pbrooks259]

As best as I can tell vertical roller wear marks on the calibration sheet are being transferred to scanned images causing white vertical lines to appear in scanned images.

I purchased a new calibration sheet, used it, and that took care of it.

Thanks for your replies, guys.