Question For The List

I know!. Even I don't normally do it, but I have taken old cartridges apart as part of figuring out just how the laser printer in question works ('Aha, that contact goes to the primary corona wire, that one to the drum gronnd', etc). I would consider rebuilding a cartridge if it was for a classic laserprinter for which cartridges were no longer available (like 'homebrew' [1] Canon CX-VDO on my PERQ) [1] This printer started out as a Canon LBP8-A1. A PAL chip (actually a HAL, which is a mask-programmed PAL) chip on the formatter board failed. Canon don't supply service information or parts (I later found I could have got a complete replacement board, but I doubt I could have afforded it). Anyway, thanks to Bob Davis and others, I found out that the PERQ could take a direct-drive ('video interface') laser printer that was based on the same engine. I managed to get an assortment of part-stuffed PERQ interface cards and the schematics for that, assembled one fully, took the printer apart into very little pieces, worked out how that worked, matched up signals, made cables, etc. And finally put it all together. No it didn't work. But it nearly did. After a bit of tracing, I found I'd missed a jumper wire off the interface board. Fitted that, it worked fine. After all that work, you can bet I am going to try and keep that going. It's like my HP45 calculator. That's a common-ish model anyway, and mine is worthless to a collector, it's got half the legends rubbed off, not all the display digits are the same size, the batter contacts are corroded, etc. But I built that machine from bits a friend was giving away -- A&R chip from one board, other chips from another board, PSU converter transsistor from the junk box, and so on. As such, it means a lot to me. It's time for the story fo the toner and the toilet :-). A friend of mine has an SX-engined printer, and he managed to convince me to show him how to take the cartridge apart (I'd already one one of mine, so I knew what came off in what order). Anyway after removing the outer casing and separaing the 2 sections from the drum, we came to the waste toner collector. And he decided to empty it -- into the toilet. It was at this point we discovered that toner floats on water, and wouldn't flush away. Fortunately, one of us had the idea to add washing up liquid. That produced the most amazing black foam that finally did flush away. Depends on what's wrong with them. One of mine died when a PSU fell onto it. The PCB was crackd into several pieces. Amazingly there was a schematic on the box it had some in, which I'd cut out and filed, but it was incorrect (keys were not where they were shown in the matrix). That took an evening to sort out! -tony