Weird double printing issue in HP Laserjet / PostScript



I think I have a challenging problem that I'd like to share with you,
to see if anyone else has an explanation as to why this might be

Our IBM AIX 5L based computer system has a bunch of images stored on
it. The images are scanned on an HP Scanjet, saved in TIF format, then
transferred onto the AIX server for storage. If anyone wants a copy of
the scanned image, we take the TIF and convert it to Postscript to add
a border around it showing the filename, date it was printed, and a
few other details. The converted PS file then gets sent to an HP
Laserjet printer using PostScript drivers.

This worked fine for the first 6818 images we've scanned in over the
last few months.

Recently, when we have been trying to print any new images scanned
(image number 6819 and higher), the image comes out blurred, almost as
if you were seeing a scan of the image overtop of another copy of the
image that was displaced slightly left. This is ONLY on the TIF
section in the middle of the document, as the filename, date printed,
and border we put on is NOT blurred.

If we view the TIF image on the screen, it is NOT blurred. If we take
the TIF and send it via email to someone, it shows fine on their

After trying a whole bunch of things, we finally determined that the
following scenarios are true:

1) Images # 1 to 6818 can be printed fine on our primary HP Laserjet
(Printer A)
2) Images # 6819 and up print blurred on the primary HP Laserjet
(Printer A)
3) Any and all images will print fine if sent to a different HP
Laserjet (Printer B)

The printers are the set up the same way on the AIX server, using the
qdaemon/LPD services, and using a generic PostScript driver. Our
server has not received any updates that would change the drivers or
the "TIF to PS" converter. Our PC scanner and software did not change.
So I am baffled why it would work for many months and then suddenly
refuse to print newly scanned images properly.

Our solution is more of a workaround. We simply replaced the primary
printer with the secondary printer that we know can print ALL the
images without any problem. But it does not explain why the OLD images
will print but the NEW ones do not on one of our printers, and it
literally happened overnight.

I am the type of person that likes to know WHY something happened, but
I only have theories at the moment:

1) Perhaps the Windows PC received a Microsoft update that updated
some DLLs and changed how our HP scanner saves its TIF data. MS Update
is configured to automatically install any updates, so could have
changed stuff without us being aware. But if this did happen, I would
have expected it to affect ALL printers, not just the main one we use.

2) Perhaps the primary HP printer memory or firmware has been damaged
(electro-static?) and this affected the built-in logic that handles
PostScript data. Again, if this occurred, I would have expected ALL
images we scanned to have a problem printing to that printer, not just
the more recent ones.

3) Somehow the conversion software that changes the TIF to a
PostScript file has been damaged. But again, this would affect every
image we convert so we can print, not just the ones over image number

Has anyone else encountered something similar to this? Or do you have
a possible explanation for the behaviour?

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question