Printer help?

der Mouse <mouse(a)rodents.montreal.qc.ca> wrote: Where was it? I thought it was on one of the PSU boards, but you now seem to imply it's on the DC controller. The control panels lights and LCD are controlled by the formatter board. That's the big one on the right, the one that memory and PostScript options go onto and MIO cards and font cartridges go into, and the only board in the entire printer that makes it an HP LaserJet IIISi as opposed to, say, DEC LPS17. The fact that it walks the lights, enters the self-test and knows about PS indicates that the formatted board is probably OK. The formatter board talks to the DC controller, which is the main print engine controller, which controls the entire Canon-built NX engine. The formatter board throws up a 55 error if it can't talk to the DC controller. If the board you are having woes with, the one damaged by the blown cap, is indeed the DC controller board, then it's probably the culprit. The DC controller board is in the front right area of the printer, below the control panel, directly behind the plastic front cover. If you take a close look at the front cover between the tray openings and the font cartridge slots, you'll see a small hole. This hole provides access to the engine test button on the DC controller board. If you push this button, the DC controller will print an engine test page independently of the formatter, i.e., it'll forcibly override whatever the formatter is directing it to do and will work even if the formatter is missing or dead. Try it. But it looks like your problem is the opposite, good formatter and bad DC controller. There are no sensor switches for the plastic covers. There are sensors for fans and it'll halt if any fan is unplugged. The AC input assembly in the PSU area has an interlock switch that cuts off the AC to the fuser and the "B" side of +24V DC that powers the main motor, the laser, and the high voltage supply for the imaging system if the top is lifted. The "A" side of +24V DC that powers all logic is always on. The only other interlock switches are the higher-level "top open" switch that doesn't cut off any power, but tells the thing to stop and complain about the open top on the LCD, and the EP cartridge presence detect switches. -- quoting: -- The "55 Service" error indicates that the printer failed to initialize correctly at power ON. This means that the Formatter cannot communicate with the engine in order to establish the initial condition of the engine. This problem can be caused by a bad Formatter, bad cable, or by problems with the line voltage. Check and reseat connectors J4 and J5 on the DC Power Supply, and J8, J9, and J10 on the DC Controller PCA. Cycle the power several times to clear the error or to get another error that may better indicate the cause of the problem. If this clears the error, run an engine test print. If the error persists, replace the Paper Pickup PCA, the DC Controller PCA, the DC Power Supply PCA, the Formatter PCA. Finally, replace the Paper Input Unit. If these fail to correct the problem, check all associated cables for damage and replace if required. Any 57.1 Main Motor problem can also cause this error. -- end quote -- I think you are talking about the DC controller board. Someone just posted about having a bad HP 4SiMX for free for the taking. He said it jams, so that's probably a mechanical problem and the electronics is probably OK. He is in California (Bay Area), i.e., nowhere near you, but if you can convince him to take out and send you the formatter and the DC controller boards, that might work for you. You'll need both boards and the cable between them since it's a 4Si. Since the two printers are otherwise identical, swapping those two boards will turn your IIISi into a 4Si, i.e., you'll get 600 DPI and PostScript Level 2. You might also need a few other bits like the control panel (I'm not sure if they changed it), but nothing major and certainly nothing heavy. And if you two do work out that arrangement, I could take the rest for spare parts next time I'm in the Bay Area. (I'm in Southern Calif.) MS