Printer help?

From: Michael Sokolov <msokolov_at_ivan.Harhan.ORG>
Date: Thu Sep 9 11:40:17 2004

der Mouse <> wrote:

> Does the collective list wisdom include repair hints for an HP LaserJet
> IIISi? I have one.

I have a 4Si, and as I've learned through 20/20 hindsight, it's exactly
the same printer as the IIISi with the exception of two electronics
boards (the formatter and the DC controller) which have been redesigned
to do 600 DPI. The outside box and every internal part except for those
two boards are exactly identical.

I wish I had known this at the time I got mine. In July I went on a
truck trip with Fred van Kempen to Mountain View, Calif., and as we
were walking through town to his house after having left the truck at
his office, we stumbled across a LaserJet IIISi left out to pasture by
the side of the road. I wanted to pick it up and take it with me on the
truck back to Southern Calif., but Fred strongly dissuaded me ("Mike,
don't bother with this piece of junk, it's a 3 and you want a 4").
Had I picked it up and taken it, I would have probably saved a bunch
of money on replacement parts I had to get for my 4Si after I got it
to make it work fully.

I got my 4Si from eBay for $60 (plus $99 for shipping), and as one can
expect for this price, it came completely stripped of everything optional,
i.e., of everything that isn't required for it to come up and print a
test page. It came with only the base 2 MB of memory (perfectly reasonable
for a little personal laser printer, but an insult for what's supposed
to be a high-end print server), and of course my sheepish hopes of getting
a PostScript module and/or a duplexer with it were dream, dream.

There was one surprise of the pleasant kind, though. It was listed on
eBay as having an Ethernet MIO card, but it came with a serial MIO card
instead. Not even serial/parallel, just serial. Whoo-hoo! Purrfect!
Of course everyone else in the world wants Ethernet and considers serial
slow old stuff, I am me. :) One thing I did take from the IIISi in
Mountain View was the serial/parallel MIO card, but I ended up not needing
it. Just serial is better for me. Besides, unlike the IIISi one,
the 4Si formatter board has a built-in bidirectional parallel port
(something I very much disgust because it's so non-Classic) and having
two parallel ports on the back only one of which is working would just
look ugly.

The bad news was that it would only print to the rear output slot, and
any attempts to print to the main upper output bin resulted in front
panel error messages about jams. I've called PrinterWorks (great laser
printer gurus, and they advised me to replace the
job offset assembly. But I was still stuck at the point of not knowing
how to take the sucker apart. OK, it was obvious how to get to the
formatter board to add the PostScript ROM and memory SIMMs, but the
engine resisted my attempts to figure out how it comes apart.

So I went looking for a service manual. Found found on eBay in PDF
on CD, bought it, had to wait for the CD to arrive, then go to Kinko's
and have the PDFs printed. It was a pretty good deal: in addition to
the combined IIISi/4Si service manual from HP (which is what made me
realise that they are the exact same printer), there was also a generic
laser printer repair book that taught a lot of general principles not
specific to any given make or model, and approched things from a rather
Tony Duell-like perspective.

With the help of the service manual (OK, part swapper guide) I figured
out how to take the sucker apart. I got to the job offset assembly and
took it out for examination. It was dirty with grease, but not in the
paper path, and there wasn't anything obviously wrong with it. I was
hesitant at first about just buying a new job offset assy and trying to
swap it in and see what happens, having heard Prof. Duell's admonitions
against randomly swapping parts. But then I broke down and did it, as
there was just nothing wrong I could see, it just didn't work. Familiar
feeling, eh? Absolutely nothing wrong, it just doesn't work... Well,
after buying a new job offset assy and putting it in, the problem went
away and the printer now happily prints to the main output bin. I will
never know what was wrong with the old job offset assy as the shop I
bought the new one from required a core return. (By the way, even though
job offset is a feature I absolutely don't need and have turned off,
the job offset assy is a required part of the print engine and must be
present and in good order whether you need job offset or not.)

Then I needed to fatten it up with options. I needed the PostScript
module of course (I consider PostScript to be the one and only printer
language, so a laser printer without PostScript is a boat anchor to me),
and I got it even before I fixed the main output bin woes. On the 4Si
the PostScript module is a ROM SIMM that takes up one of the 4 SIMM slots.
It's PostScript Level 2. After I got the main output bin working, I
bought the duplexer from PrinterWorks. One of the reasons I needed a
high-end printer is to print big specs and other stuff to go into 3-ring
binders, so duplex printing is very important. It works, so I'm happy.
Of course I needed to get more memory too. It was not happy at all
with the duplexer and PS in there and only 2 MB to live in. Fortunately, I
found a set of 3 compatible 8 MB SIMMs (maximum with one slot tied up by
the PS ROM SIMM) on eBay for dirt cheap and now I have 26 MB total, the
maximum with PS. It now works like a charm, configured for PostScript
only (I like the pretend that PCL is not there), with an H8571-E MMJ
adapter fitted into its stupid female DTE connector and connected to its
driving 4.3BSD-Quasijarus host with a DECconnect MMJ serial cable, or
The One True Interconnect.

I wrote the 4.3BSD-Quasijarus support for it, which will appear in the
next release. Since it'll be released, I wrote the code for pure
PostScript: it assumes a pure PS printer like the original Apple LaserWriter
or DEC LN03R (something I would very much love to have for fun and
experimentation, but unfortunately lack) and never allows the HP printer
to fall out of PostScript mode into PCL. Plain text given to lpr is
converted into PS by txtps, a 4.3BSD-Quasijarus utility, and *not* sent
to the printer as-is. I also added functionality to lpd to control options
like duplex (so I can do lpr -Php4si -Oduplex, and it's implemented
using PostScript Level 2 standard setpagedevice operator, NOT HP proprietary
stuff like PJL commands. (Of course it's open source and modular, though,
so if you need to modify it to work with your PostScript Level 1 printer,
you can make it do whatever is necessary, provided that you can figure it out:
I have no idea myself how to, for example, programmatically turn on duplex
on a IIISi with PostScript Level 1.)

> Yesterday, I turned it on, same as a zillion times
> before, and it didn't come up normally; it was making an odd ticking
> noise. I went to see what was up and smelled that unpleasant smell
> that usually means the magic smoke has been let out of something.

Reading the follow-up posts in this thread, I see that you've already
found the failed PSU capacitor, so (hopefully) you should be all set once
you find time to replace it. Feel free to ask again if you need more
help or a copy of the service manual. After all this tinkering with
mine (cleaning it inside out, getting to and replacing that job offset
assembly, and fattening it up with options), I feel like an expert on
the NX engine.

Yes, like just about every laser printer in the world, it's a Canon engine,
and this one is NX. The word engine is a bit misleading: I originally
thought it meant something internal and did not include the outside
appearance of the printer and input/output options like paper trays.
As it turns out, NX engine means not just some inside guts like the
laser or the motor, but the entire printer from plastic covers outside
to the last screw inside is made by Canon. The ONLY HP part in there
is the formatter with its associated I/O ports and font cartridge slots
on the right side of the printer. This means that other printers based
on the same engine will not only have some similar parts inside, but
will look exactly identical outside except for a different logo painted
on the top plastic cover, and the insides will be identical to the last
screw rather than just share some common parts. Whew! I really did not
expect that, I thought there was more diversity in the printer world.

As some people may remember, prior to deciding on buying this HP 4Si,
I was asking on this list a bunch of questions about DEC PrintServer 17
(LPS17), which was another printer I was considering. Well, imagine my
amazement when I learned that it is also based on the NX engine and that
the two printers I was debating between (LPS17 and HP 4Si) are in fact
exactly the same printer with a different formatter board fitted in the
pan on the right! Small world...

The NX engine has 300 DPI and 600 DPI versions, and the difference is
only in the DC controller board. Every other part is the same, as are
options like the duplexer. Formatter boards would be different too,
not just between HP IIISi and 4Si (which have a bit more significant
differences at the formatter/personality level), but other folks like
DEC who used the NX engine would have had to redesign the formatter
board for the higher resolution when going from NX/300 to NX/600.
But still, it's an interesting thought that all paper handling options,
i.e., the duplexer, high capacity sheet and envelope feeders, etc.,
and even the plain paper trays are exactly the same between HP IIISi,
HP 4Si, DEC LPS17, probably others...

Speaking of paper trays for NX printers, I wonder if anyone here might
have one piffling little plastic part they would be willing to part with.
Do you know the metal plate/bar that goes across the tray near its back
(most protruding) end? That metal plate/bar has two plastic pivots on
its side that hold it in the tray. The right pivot in one of my trays
is broken, but the tray is perfectly fine otherwise. Since it's just
this piffling little plastic part that needs replacement, I really don't
want a whole new tray. It's not a matter of cost, I just don't want
another tray, I want to fix the one I have. The piffling little plastic
part I need has a part number, RB1-1074, it's molded into the plastic
and it's a Canon part number, so it's the same whether it came from Canon
to you through HP or through DEC or however. But no printer parts store
is willing to sell me that piffling little plastic part, they want to
sell me another tray that I don't want. So I wonder, would someone here
happen to have a spare RB1-1074 that I could have? Perhaps from a broken
tray that's broken in another way? TIA,

Received on Thu Sep 09 2004 - 11:40:17 BST

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