Printer help?

der Mouse <mouse(a)rodents.montreal.qc.ca> wrote: 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, www.printerworks.com) 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 mydoc.ps), 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.) 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, MS