PRINTER MAINTENANCE by Loyd Couch The use of my printer, an NX1000, is basically limited to responding to correspondence received by CIVIC 64/128, and for preparing mailing labels for distributing newsletters and labels for copies of library disks, newsletter disks, and Disk-of-the-Month. I use single sheet paper because my responses seldom exceeds a page. Thus, I leave the single width, sprocket fed mailing labels installed all the time, ready to print with the flip of a lever. Maintenance of the printer has been limited to re-inking or replacing ribbons. Printer performance thus deteriorated. Blank lines began appearing when printing the Users Group logo, indicating sticky print head pins. When printing labels, the paper would frequently jump sprockets at the fold, indicating weak sprocket cover pressure. Rolf Miller noticed the logo problem and said that he had success cleaning print head pins by soaking that part of the print head in alcohol for a couple of hours. I used denatured alcohol, and after soaking for two hours, the pins of the print head of my printer worked fine. A very easy maintenance routine. While the pins were soaking, I corrected the sprocket cover problem. This was accomplished by taping a 3/4 inch by 3 3/8 inch piece of 1/4 inch thick cardboard to the printer's rear cover such that it pressured both sprocket covers. The length allowed the cardboard to apply the pressure without interfering with the sprocket wheels. The corrections were simple and should have been done much earlier. Lesson learned: repairs performed as needed keep repair and operating efforts to a minimum in addition to keeping the equipment operating properly. Cleaning a print head is not difficult. Most printer manuals show how to remove the head for replacement and, naturally, the head must be removed to clean it. If a manual is not possessed, look for the screws that secure the head, but before removing them, find and unplug from the board the ribbon of wire that runs to the head. (Instead of unplugging the ribbon cable, I just freed it enough to allow dipping the pin face of the head in a cut down yogurt cup filled with alcohol.) Once removed, let the pins - just the pins, not the entire head - soak in the alcohol a few hours. Then use a SOFT brush - not a toothbrush - to finish the job of removing any dirty stuff still clinging around the head area. (Do NOT lubricate. The ink used for dot-matrix printers contains a lubricant.) Finally, remount the head and do a self-test or some printing to make sure everything is working properly. The need to clean a print head becomes evident when printing shows ill-formed characters. Characters are formed by a series of dots produced by the pins. Missing dots are the result of sticking pins. This condition becomes more apparent as the head heats up from continuous printing. The malady is the result on a build up of gunk (a mixture of ink, dust, fibers) around the pins which causes them to stick instead of "firing" properly. (From CIVIC 64/128 GAZETTE, June 1997, via the Commodore Information Center http://home.att.net/~rmestel/commodore.html )