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Laser printer gloat...

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Jeff Liebermann...

Posted: Wed Nov 04, 2009 1:25 am

Guest

On Tue, 03 Nov 2009 21:07:50 -0800, David Nebenzahl
<nobody at (no spam) but.us.chickens> wrote:

[quote]In case I wasn't clear, the problem I was referring to was printing a
document on both front and back, where you first print the odd pages,
then run the stack back through on the other side and print the even pages.

Every non-duplexing HP LaserJet I've ever seen will fuck up and jam if
you try to do this. The problem, as you said, is the curl imparted to
the paper by the fuser. I have had some success taking the first-printed
stack and "working" it vigorously to remove the curl, but it's a pain in
the ass, and not guaranteed to work.
[/quote]
Yep. You also have to let the stack cool down a bit. I also listed
some other problems that can cause paper jams when trying to print
double sided without a duplexer.... (cut-n-paste):

The printers expect the pages to be flat. Pages that have gone
through the printer tend to be slightly warped. That causes paper
jams. Remelting the toner on the back side of the page sometimes
causes the toner to stick to the rubber roller in the fuser, causing
exit jams. Paper doesn't like to slide smoothly off the stack in the
tray when there's printing on the back side. That's an especially bad
problem if you print a stack of paper, and then feed the stack back
through the printer again to print on the back side. The pages will
stick together. The rubber "feet" above the feed tray don't like to
push against printed paper, where the black areas are much slicker
than the unprinted white paper. It's usually not a problem with a
fairly new printer, but after the rubber feet get worn and slick,
things tend to slide.

[quote]Since there are other laser printers that don't have this problem, I can
only conclude that HP LaserJets have inferior feed mechanisms.
[/quote]
Yep, but there's a bit of a complexication. HP likes to built
printers that have a small footprint. That means that the paper
trays, which are always at the bottom of the pile, have to feed the
paper to the printer after making a 180 degree tight turn out from the
tray. The Panasonic 450(???) printer you mentioned had an externally
projecting paper tray, that allowed for a more straight line paper
input feed. That 180 degree turn is always a problem.

However, I do agree that HP could do a better job with their feed
mechanisms. The fix is rather simple. The typical Laserjet has the
absolute minimum amount of rubber in contact with the paper. Large
copiers have similar mechanism, but with much larger rollers on both
sides of the paper to maximize grip. They also have much thicker and
softer rubber feed rollers to maximize friction. If you want a really
reliable paper feed, it will look like a straight line offset press.

If you look carefully at the typical HP Laserjet, there are at least 5
feeds. I'll use the HP LJ 4000 as an example. The first is a simple
roller in the paper tray to get the paper started. After a 180 degree
curling turn, it goes to 4 D-shaped pickup rollers, which really do
the work. Under the paper is the separation roller, which supplies
pressure to the imaging drum. The paper then gets fed into the fuser
roller, and then to a series of exit rollers. Any one of these can
screwup and cause feed problem. Most common is the separation roller,
which is made of foam, getting clogged with toner. Next is the
polishing of the D-shaped pickup rollers from sliding across the paper
when the feed rollers slip slightly. The paper tray input roller
usually feeds correctly, but the paper can jam up against dirt and
filth on the tray in the area around the feed roller. Shredded paper
in the fuser assembly will usually stop the paper and cause a jam.
Exit rollers are usually fairly reliable, except when the fuser craps
out and the rollers get covered with toner.

[quote]And I do know what the hell I'm talking about: in a previous life I was
a printer (as in a real printing press, not desktop computer printers),
so I've dealt with lots of machines that eat paper.
[/quote]
Full disclosure: I sometimes fix HP Laserjet printers. However, I'm
not factory trained or authorized. In the 1970's, I briefly owned a
commercial print shop. Mostly AB Dick and some Gestetner. I didn't
do the printing, but I sure got the complaints when they didn't work.
I also ran the college print shop and got some experience on hot lead
Linotype presses and Compugraphic (Harris) typesetters.

--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

David Nebenzahl...

Posted: Wed Nov 04, 2009 2:30 am

Guest

On 11/3/2009 10:25 PM Jeff Liebermann spake thus:

[quote]However, I do agree that HP could do a better job with their feed
mechanisms. The fix is rather simple. The typical Laserjet has the
absolute minimum amount of rubber in contact with the paper. Large
copiers have similar mechanism, but with much larger rollers on both
sides of the paper to maximize grip. They also have much thicker and
softer rubber feed rollers to maximize friction. If you want a really
reliable paper feed, it will look like a straight line offset press.
[/quote]
Yeah; if only we could have desktop printers with feeders as reliable as
the one on the Heidelberg Speedmaster I used to "own" ... now *that's* a
feeder!

--
Who needs a junta or a dictatorship when you have a Congress
blowing Wall Street, using the media as a condom?

- harvested from Usenet

Roger Blake...

Posted: Wed Nov 04, 2009 4:40 am

Guest

On 2009-11-04, David Nebenzahl <nobody at (no spam) but.us.chickens> wrote:
[quote]Got my HP LaserJet 2100M (600 DPI w/PostScript capability) ca. 2000. Not
only is the printer still working perfectly, but I'm still using the
same cartridge I got with it!
[/quote]
My Canon LBP-430 (same as an HP LaserJet 4L) is still soldiering on
after 15 years. I have changed the cartridge a couple of times, and
recently scored a few very inexpensive toners at a thrift store
to keep it going another 15 years. :-)

--
Roger Blake
(Subtract 10s for email. "Google Groups" messages killfiled due to spam.)
"Obama dozed while people froze."

Meat Plow...

Posted: Wed Nov 04, 2009 6:55 am

Guest

On Tue, 03 Nov 2009 16:56:06 -0800, David Nebenzahl
<nobody at (no spam) but.us.chickens>wrote:

[quote]This inspired by the mini-thread in the thread up yonder about HP
DeskJet printers. Actually something of a reverse gloat, along the lines
of "my old printer still works; does yours?".

Got my HP LaserJet 2100M (600 DPI w/PostScript capability) ca. 2000. Not
only is the printer still working perfectly, but I'm still using the
same cartridge I got with it!

Which is a little puzzling; while the printer hasn't exactly been used
in a production environment, I have put plenty of pages through it:
printed out many entire manuals, etc. I'm just waiting for the cartridge
to empty out, but it still hasn't come close. (I even have a 2nd
cartridge I got with the printer, still in its foil package.)

One thing I really don't like about this, and really most HP printers
that I've used, is that it hates to print on the back of printed sheets.
Usually it eats/shreds about half the sheets one tries to print this
way. Yeah, I know, you can get HPs with "duplex" options, but to me,
that's utter bullshit. I remember the old Panasonic laser printer my old
office had. It was a huge beast, and certainly no better than the HP we
also had at the time (LJ 4???), but the Panasonic would feed *any* paper
you put into it, even if it had just been run through the printer on one
side. I'd always use it to print out my manuals on 2 sides for proofing.

Other than this, the LaserJet is a fine piece of equipment.
[/quote]
I've installed networked HP lasers since the 4M with network card
installed was the latest and greatest. I've seen some of those with
page counts upwards of 100,000 having nothing major done besides
a cleaning.

baron...

Posted: Wed Nov 04, 2009 8:12 am

Guest

David Nebenzahl Inscribed thus:

[quote]This inspired by the mini-thread in the thread up yonder about HP
DeskJet printers. Actually something of a reverse gloat, along the
lines of "my old printer still works; does yours?".

Got my HP LaserJet 2100M (600 DPI w/PostScript capability) ca. 2000.
Not only is the printer still working perfectly, but I'm still using
the same cartridge I got with it!

Which is a little puzzling; while the printer hasn't exactly been used
in a production environment, I have put plenty of pages through it:
printed out many entire manuals, etc. I'm just waiting for the
cartridge to empty out, but it still hasn't come close. (I even have a
2nd cartridge I got with the printer, still in its foil package.)
[/quote]
If I remember correctly the toner cartridge was good for about 10K
pages.

[quote]One thing I really don't like about this, and really most HP printers
that I've used, is that it hates to print on the back of printed
sheets. Usually it eats/shreds about half the sheets one tries to
print this way. Yeah, I know, you can get HPs with "duplex" options,
but to me, that's utter bullshit. I remember the old Panasonic laser
printer my old office had. It was a huge beast, and certainly no
better than the HP we also had at the time (LJ 4???), but the
Panasonic would feed *any* paper you put into it, even if it had just
been run through the printer on one side. I'd always use it to print
out my manuals on 2 sides for proofing.

Other than this, the LaserJet is a fine piece of equipment.

[/quote]
The old Panasonic's were great printers ! As you remark it would print
on anything including the back of already printed sheets. Ours was
used with two and three part NCR paper. The hard part was the software
to ensure that it registered and collated properly.

The bottled toner was very cheap as well which made the machine very
economical compared to similar machines.

--
Best Regards:
Baron.

PeterD...

Posted: Wed Nov 04, 2009 8:45 am

Guest

PeterD...

Posted: Wed Nov 04, 2009 8:48 am

Guest

On Tue, 03 Nov 2009 19:34:53 -0700, D Yuniskis
<not.going.to.be at (no spam) seen.com> wrote:

[quote]Unfortunately, even printing 8.5x11 photos (i.e., 100% ink coverage)
I haven't been able to "empty" any of them!
[/quote]
You are just not printing enough!

[quote]You've either got bad rollers, a bad fuser or "off brand" toner.
[/quote]
Pickup rollers probably, clean with acetone as a first step try. Then
replace 'em.

[quote]...
I couldn't *kill* my LJii! I finally had to get rid of it as
the electric costs were ridiculous (though the toner carts
were awful cheap!)
[/quote]
Make a wonderful space heater for winter, however. Keeps my office
toasty warm!

William Sommerwerck...

Posted: Wed Nov 04, 2009 10:00 am

Guest

[quote]Nope. Not the problem. It's inherent in the lousy HP feeder design. I've
never seen a LaserJet that would print on the back side of just-printed
sheets even when brand new.
[/quote]
My 4M will. However, there's no question that it's not a bad idea to let the
paper cool down and flatten out.

Jeff Liebermann...

Posted: Wed Nov 04, 2009 11:01 am

Guest

On Tue, 03 Nov 2009 23:30:22 -0800, David Nebenzahl
<nobody at (no spam) but.us.chickens> wrote:

[quote]Yeah; if only we could have desktop printers with feeders as reliable as
the one on the Heidelberg Speedmaster I used to "own" ... now *that's* a
feeder!
[/quote]
Ummm.... sure:
<http://www.heidelberg.com/www/html/en/content/overview1/products/sheetfed_overview-qg>
I'm not familiar with it, but my guess is that it uses vacuum pickup
to handle large format and heavy items, such as box cardboard. Such
technology doesn't scale well for the home and small biz printer.
Ignoring the size, price tag, skill level, ink handling, and required
accessories (i.e. dryer), the home version of this beast would
probably make so much noise that it would be unsellable. Still, it
might be possible to borrow some of the paper handling technology and
use it for small printers. For example, instead of pick and plop
vacuum paper handling, the feed rollers could use vacuum to grab,
hold, and eventually release the paper. I suspect that this may also
become a vacuum cleaner, sucking up dust and filth from the
surroundings, but that can be handled by occasionally reversing the
air flow and blasting the dust back into the owners face, until they
get the clue.

Having seen miniature engines, metal working machinery, and
automobiles, I suspected that someone might build a miniature offset
press that could be adaptable for home use. There's a 1937 patent:
<http://www.google.com/patents/about?id=fOo-AAAAEBAJ&dq=2099962>
which is not very useful. Google found some vendors in China and
India that sell miniature offset presses. However, their idea of
miniature is about the size of refrigerator. I couldn't find anything
the size of a typical inkjet printer. So, there's your dot.com
opportunity. Design and sell mini-Heidelberg style offset presses for
those home users that need to print on all manner of wrinkled,
pre-printed, warped, filthy, and disgusting paper without a paper jam.
Incidentally, forget about cut sheet paper. Roll feed is far faster,
cheaper, and generally better.

--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann...

Posted: Wed Nov 04, 2009 11:26 am

Guest

On Wed, 04 Nov 2009 06:55:17 -0500, Meat Plow <meat at (no spam) petitmorte.net>
wrote:

[quote]I've installed networked HP lasers since the 4M with network card
installed was the latest and greatest. I've seen some of those with
page counts upwards of 100,000 having nothing major done besides
a cleaning.
[/quote]
I beg to differ somewhat. The HP LJ4 series does have some chronic
wear parts that cause problems.

Number one on the paper jam causing list is the rear rubber feed
roller assembly (4 rubber rollers on a shaft) located in the back of
the printer (RF5-1077). Microscopic changes in diameter of this
roller causes the paper handling to loose sync with the exit rollers
(RF5-1076) at the top of the printer, causing a nasty paper jam at the
exit roller. Since the two sets of rollers contact the paper at the
same time, they have to be operating at exactly the same effective
paper speed or it will jam. I usually replace both the upper and
lower exit rollers to be sure.

The tray 2 rubber feed roller (RB1-3477) is also a chronic problem. It
tends to get polished when it slips, resulting in insufficient pickup
traction. That causes misfeeds from the tray.

The foam rubber transfer roller (RF5-0349) will eventually get clogged
with white clay paper coating and paper dust and need to be cleaned. I
wash these in soap and water, but that takes time to dry. So, I
usually replace the transfer roller with a new or cleaned roller.

Plenty of repair kits available on eBay and elsewhere:
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260291368693>

My favorite printer repair tool... an air compressor. However, do it
outside.

About 10 years ago, I maintained a few HP4 series printers. A billing
service had one with 300,000 pages. I replaced some minor plastic
parts that had worn out, and I think it ran for another 20,000 pages
before being retired. My HP4Plus went to about 130,000 pages. I know
of several others that are around 100,000 pages. Yep, they last as do
the older HPII and HPIII series printers. However, I won't say
anything nice about the envelope feeder attachments. They're really
awful and a common reason for customers to upgrade to a better
printer.

--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann...

Posted: Wed Nov 04, 2009 11:39 am

Guest

On Wed, 04 Nov 2009 13:12:18 +0000, baron
<baron.nospam at (no spam) linuxmaniac.nospam.net> wrote:

[quote]The old Panasonic's were great printers ! As you remark it would print
on anything including the back of already printed sheets. Ours was
used with two and three part NCR paper. The hard part was the software
to ensure that it registered and collated properly.
[/quote]
The old Panasonic KX-4450 series laser printers were awful. When
clean, they would work just fine. They didn't jam because the
projecting paper trays would simulate a straight line paper path. They
did bar codes, which was a big attraction at the time. However,
keeping them running and clean was a challenge. I had one in a
machine shop that was as good as dead after about 30,000 pages.
Another was in a small factory next to a farm that ate enough dirt to
destroy almost all the rubber parts. The toner overflow mechanism was
messy and would frequently dump toner everywhere. It was instant
quality problems from "clumping" if someone dumped the "waste" toner
back into the toner bin. Much as I liked the economy of the bottled
toner, it was messy to refill. Because of the open toner bin
construction, I couldn't keep it clean with an air hose. There were
two in relatively clean environments that lasted to about 70,000
pages, but they required almost constant cleaning to remain
functional.

[quote]The bottled toner was very cheap as well which made the machine very
economical compared to similar machines.
[/quote]
True.

--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

David Nebenzahl...

Posted: Wed Nov 04, 2009 2:14 pm

Guest

On 11/4/2009 8:01 AM Jeff Liebermann spake thus:

[quote]On Tue, 03 Nov 2009 23:30:22 -0800, David Nebenzahl
nobody at (no spam) but.us.chickens> wrote:

Yeah; if only we could have desktop printers with feeders as reliable as
the one on the Heidelberg Speedmaster I used to "own" ... now *that's* a
feeder!

Ummm.... sure:
http://www.heidelberg.com/www/html/en/content/overview1/products/sheetfed_overview-qg
I'm not familiar with it, but my guess is that it uses vacuum pickup
to handle large format and heavy items, such as box cardboard.
[/quote]
Yes. Like most real printing presses (as opposed to smaller "presses"
that are somewhat disparagingly called "duplicators"), the feeder uses
vacuum pickup, assisted by air blowers to separate the top sheets of the
stack. The Heidelberg feeder was pretty cool: it somewhat
counterintuitively picked up the sheet at the *back* and fed it forward.
Really cool to see a "stream" feeder in operation. When properly
adjusted, performs flawlessly.

[quote]Still, it might be possible to borrow some of the paper handling
technology and use it for small printers. For example, instead of
pick and plop vacuum paper handling, the feed rollers could use
vacuum to grab, hold, and eventually release the paper.
[/quote]
That would be kewl.

[quote]Having seen miniature engines, metal working machinery, and
automobiles, I suspected that someone might build a miniature offset
press that could be adaptable for home use. There's a 1937 patent:
http://www.google.com/patents/about?id=fOo-AAAAEBAJ&dq=2099962
which is not very useful. Google found some vendors in China and
India that sell miniature offset presses. However, their idea of
miniature is about the size of refrigerator. I couldn't find anything
the size of a typical inkjet printer.
[/quote]
Ackshooly, the AB Dick 320 offset duplicator was a table-top model only
slightly larger than the larger laser printers of the early days. I
first learned to print on one of those, using direct paper plates (you
typed and wrote directly on the plate using special ribbons and pencils,
almost like a mimeograph). But the 320, being a dinky "press", used
friction feed (rubber rollers) which of course isn't nearly as good as
vacuum feed.

--
Who needs a junta or a dictatorship when you have a Congress
blowing Wall Street, using the media as a condom?

- harvested from Usenet

Warren Block...

Posted: Wed Nov 04, 2009 2:47 pm

Guest

Jeff Liebermann <jeffl at (no spam) cruzio.com> wrote:
[quote]
About 10 years ago, I maintained a few HP4 series printers. A billing
service had one with 300,000 pages. I replaced some minor plastic
parts that had worn out, and I think it ran for another 20,000 pages
before being retired. My HP4Plus went to about 130,000 pages. I know
of several others that are around 100,000 pages. Yep, they last as do
the older HPII and HPIII series printers.
[/quote]
I know of at least one LJ4050 that's over a million pages, and others
approaching that. The fusers wear out a bit earlier than predicted
(170-180K pages instead of 200K) and of course they've been through a
couple of sets of rollers. My old LJ4M still works, but it's not
anywhere near the class of those printers. Sometimes "new and improved"
is actually true.

--
Warren Block * Rapid City, South Dakota * USA

b...

Posted: Wed Nov 04, 2009 3:38 pm

Guest

On 4 nov, 15:40, Roger Blake <rogblak... at (no spam) iname10.com> wrote:
[quote]On 2009-11-04, David Nebenzahl <nob... at (no spam) but.us.chickens> wrote:

Got my HP LaserJet 2100M (600 DPI w/PostScript capability) ca. 2000. Not
only is the printer still working perfectly, but I'm still using the
same cartridge I got with it!

My Canon LBP-430 (same as an HP LaserJet 4L) is still soldiering on
after 15 years. I have changed the cartridge a couple of times, and
recently scored a few very inexpensive toners at a thrift store
to keep it going another 15 years. Smile

[/quote]
I have a canon LBP-4u which is also a Laserjet 4L in disguise. It was
a skip find a few years ago, and works like a champ. I also salvaged
some 4l toners to use with it should the need arise. Not sure what
resolution it is, I think it could probably be better in this
department.

-B

Jeff Liebermann...

Posted: Wed Nov 04, 2009 4:45 pm

Guest

On 4 Nov 2009 19:47:53 GMT, Warren Block <wblock at (no spam) wonkity.com> wrote:

[quote]Jeff Liebermann <jeffl at (no spam) cruzio.com> wrote:

About 10 years ago, I maintained a few HP4 series printers. A billing
service had one with 300,000 pages. I replaced some minor plastic
parts that had worn out, and I think it ran for another 20,000 pages
before being retired. My HP4Plus went to about 130,000 pages. I know
of several others that are around 100,000 pages. Yep, they last as do
the older HPII and HPIII series printers.

I know of at least one LJ4050 that's over a million pages, and others
approaching that.
[/quote]
Nice. Looking at my equipment log, I have customers with a 4000 and
another with a 4050. 125,000 and 250,000 pages respectively as of
about June 2009. I think the most pages on a single printer I've
dealt with was a payroll service, that would print almost continuously
8 hrs per day, 5 days per week, resulting in about 300,000 pages per
year. I think one made it to 600,000 pages. However, they weren't
trying to break any records, so old printers were retired as soon as
they developed any kind of mechanical problem.

[quote]The fusers wear out a bit earlier than predicted
(170-180K pages instead of 200K) and of course they've been through a
couple of sets of rollers.
[/quote]
The LJII and LJIII would occasionally burn out the fuser lamp. More
commonly, the relay in the power supply module would fry it contacts:
<http://802.11junk.com/jeffl/pics/drivel/slides/hp-relay.html>
Note the pitted contacts. The triac in the power supply would also
blow up. I spent lots of time rebuilding HP LJII and LJIII power
supplies.

More common failures in the HP LJII and LJIII fusers was a build up of
melted toner on the thermostat and on the 4 stripped blades. These
would eventually gouge the surface of the drum, and expose the
underlying aluminum. A filthy felt scrubber will also gouge the drum.
Pull the scrubber and remove any melted toner. Melted toner in the
gears was also a problem.

If you have an HP LJII and LJIII, open the top, and pull the hinged
stripper blade assembly towards the back of the printer. It's on the
back side of the fuser. No need to remove the fuser from the unit.
Take a plastic blade and scrape clean the 4 sharp stripper blades from
any melted toner. If there's a vertical stripe smear, about 1/4"
wide, about 2 inches from the left side of the page, remove the fuser,
and clean the melted toner off the top of the thermostat. The think
plastic end covers on the fuser tend to crumble or break off, but the
fuser will work without them.

I don't really know how long an HP LJII or LJIII fuser is expected to
last. I found myself rotating rebuilt fusers among my customers
roughly every 100,000 pages.

Oh yeah... air hose the filth out of the ozone filter, under the
corona wire, and on the bottom of the printer.

[quote]My old LJ4M still works, but it's not
anywhere near the class of those printers. Sometimes "new and improved"
is actually true.
[/quote]
I listed the common HP LJ4 problems in another rant. Think about
getting a rubber parts replacement kit:
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=380173905415>
The exit roller is the major culprit for paper jams.

--
Jeff Liebermann jeffl at (no spam) cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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