You are just not printing enough!
Pickup rollers probably, clean with acetone as a first step try. Then replace 'em.
Make a wonderful space heater for winter, however. Keeps my office toasty warm!
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."
My 4M will. However, there's no question that it's not a bad idea to let the paper cool down and flatten out.
Ummm.... sure:
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:
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@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
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:
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@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
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.
True.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On 11/4/2009 8:01 AM Jeff Liebermann spake thus:
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.
That would be kewl.
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
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
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.The LJII and LJIII would occasionally burn out the fuser lamp. More commonly, the relay in the power supply module would fry it contacts:
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.
I listed the common HP LJ4 problems in another rant. Think about getting a rubber parts replacement kit:
The exit roller is the major culprit for paper jams.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
I find it uneconomical to buy parts for older kit. Easier to just hunt around for one at a thrift store (the going rate for LJ4's around here is $20) -- chances are, you'll also end up with some free toner in the printer!
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
I've got an old 4m that was pulled and replaced. It was located in the front reception office of a steel fabricating plant. Only chronic problems I experienced with it were related to communication with the print spool on their Novell server. Nothing really mechanicl besides brown haze which eventually covered everything getting into the printer optics. I pulled the laser unit off and cleaned the prism and mirror maybe every 6 months. They upgraded to a 6p dual tray and gave me the 4 rather than binning it. That was in 2001.
About 6 months ago, also I recycled 3ea HP LJ 6p printers I was saving for parts. I was down to one customer with a 6mp so it wasn't worth saving much. I needed the space more than the parts. I built up one printer and gave it to the neighbors kids. No complaints so I guess they're either using it effectively for school work, or have totally destroyed it by now.
The 6p was reasonably state-o-de-art in 2001 but is a loser by today's standards. It's very slow (8ppm), very slow to start (90 sec), a slight power hog, and a desk space hog. 600dpi is ok for everything except photographs. There are a few minor mechanical issues, but basically it's a decent printer (once it warms up). I don't like the large footprint, but the fairly low profile offers opportunities to hide the printer where the taller equivalents (i.e. LJ4) don't fit. As long as the rubber parts are clean and soft, I haven't seen many paper misfeeds. The HP 03A toner cart is rated at about 4000 pages (at 5% coverage), and seems to deliver (I've never kept track).
Most of the real failures I've seen on the HP LJ 6p series were blown electronics. There doesn't seem to be a pattern as most were caused by power glitches which seems to do random damage. I usually replace the main pickup roller on the 6P and similar construction 4P when diving in because it usually requires total disassembly to replace the roller and I might as well do it while disassembled.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On 11/5/2009 7:05 PM Bob Larter spake thus:
Yes, but those were Canon-engine printers, not HPs. As Jeff L. pointed out, the HP design suffers from an abrupt turn right at the paper-pickup point, which seems to be the snag that makes printing on just-printed sheets very problematic.
Believe me, I've tried this many, many times, as I prefer to print long documents on both sides of the paper.
-- Who needs a junta or a dictatorship when you have a Congress blowing Wall Street, using the media as a condom? - harvested from Usenet
Well, something is clearly wrong. I serviced Canon-engine lasers for many years, & all the larger models (ie; with more metal than plastic, such as the CX, SX & MX engines) had really good paper-handling, & could cope just fine with double-sided printing.
--
W
. | ,. w , "Some people are alive only because
\\|/ \\|/ it is illegal to kill them." Perna condita delenda est
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The lasers I hated most were the small Toshibas - their fuser assemblies had a nasty habit of melting down. After seeing the same units coming back again & again, we eventually banned them from our workshop.
--
W
. | ,. w , "Some people are alive only because
\\|/ \\|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
The old Apple LaserWriters with Canon engines are nearly unkillable, if a bit slow. The most jam-prone printer I ever saw, though, had a Xerox engine! You'd think that if anybody knew about paper handling, it'd be them...
Isaac
Hi!
Since you asked, yes, it did. I had an HP LaserJet III that I ran the page counter over to all zeroes. All it ever asked for was the odd new pick roller and toner. It never gave any power supply trouble. In fact, the only thing it didn't have was enough installed memory to handle some jobs.
It worked great until a basement flood came along. And it might have worked even then, but it disappeared before I could even try to clean it and see what would happen.
It was pretty weird seeing a printer that old reporting a page count of a few hundred after it rolled over.
More recently, I saw a Sharp AR-M450P unit make 1.5 million copies with only routine maintenance. Ironically enough, it was more reliable than the newer (330,000 copies) AR-M450 that replaced it.
Maybe you got a never-ending cartridge? :-)
Or perhaps it is in the page coverage percentage. Printer makers express toner cartridge life at a given % of coverage on a page. I think the usual figure is based on a 10% coverage. If I'm remembering it right, 10% coverage on a page is actually a lot closer to being "fully loaded" than you'd think.
Evidently nobody ever told their dot-matrix printer design team that it was possible to do this. I had a KX-P2123 whose tractor feed had to be set up
*precisely* or it would tangle and eat the paper. I knew of many others that had the same problem. I finally dumped it in favor of an Epson ActionPrinter T1000 (a printer that proved so tough that vandals with a baseball bat couldn't break it). I haven't powered it on in a while, but I'm sure it would still work fine.William
Ummm... I think you mean CX, SX, and NX. There is no MX.
All the HP (something)X LaserJet printers were made by Canon.
Let me try to explain again, for the third time (with some additions).
The printers expect the pages to be flat. Pages that have gone through the printer tend to be slightly warped. You can demonstrate this by finding a truly flat and smooth surface, and plopping a piece of printed paper onto this surface. Flip it over and compare how it lies on the flat surface to that of a clean unprinted page. It invariable has a lump on one side or other. That's fatal to many feed mechanism, especially those that use only a single foot or roller in the middle of the page.
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. Take a page of recently printed paper and slide an unprinted page over the printed page on the flat surface. If you're careful, you can feel the increased and erratic drag. If your not a believer, hang an alligator clip on the end of a fish scale. Plop the printed page into a stack of new unprinted paper. Pull and measure the tension required to pull the paper out of the stack. Now, do the same think with an unprinted page. Depending on the height of the stack, the printed page has increased drag over the unprinted page. Yes, I know that the printer does not pull paper from the middle of the stack. The weight of the paper pile is to simulate the pressure supplied by the rubber feed roller.
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 because the black plastic toner is fairly lumpy and slightly sticky. Printing on the back side also tend to transfer some toner from the back side to the rubber roller in the fuser assembly. The HPII and HPIII were especially bad at leaving impressions on the roller. Later printers uses a mylar sheet between the fuser and the rubber roller. Reheated toner on the back of the page would not stick to the mylar.
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. I just fixed an HP 4000 printer with this problem.
In my never humble opinion, the Canon printer feed mechanism sucks. It's major problems are the reliance on a single rubber feed roller located in the middle of the page. When everything is proper (new rubber, good flat 20 lb paper, no printing on the back, etc), it works just fine. When something changes, it has so little friction surface, that it screws up badly. If there's any crud in mechanism, the center feed will cause the leading edge to misalign or corrugate, resulting in a guaranteed paper jam.
The solution was provided in the 4000 thru 4300 series printers (and some others). It has 4ea "D" shaped rubber feet to feed the paper off the top of the stack. If one foot slips a little because it's sitting on some printing or a bulge, the others will still feed the page in a fairly straight line. The "D" feet are also very easy to replace.
These later printers also solved another problem. The HP LJ4 series had two sets of coupled rollers contact the paper at the same time. If there was even a slight difference in roller diameter, the paper would either wrinkle, or the rollers would slip, and the paper would jam. Bad design. This was fixed in later models by either having only one set of rollers make contact, or adding a clutch to allow for changes in roller diameter.
Incidentally, the HP4300 records the number of pages printed on a chip attached to the toner cart. The printer records errors including paper jams. I just connected to a customers network via VNC and looked at their 4300 log file. About 10,000 pages on the toner cart with 8 paper jams. I don't think I could ever come close to that with a Canon SX series printer. This particular machine has a duplexer, but it's normally not used for tax returns. I've seen this printer grind through piles and piles of printed tax returns without ever jamming. Their previous printer was an HP4si, which would jam at least 2-4 times per ream of paper.
-- Jeff Liebermann jeffl@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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