NEC P8000 Printer Repair Secrets

If the NEC P8000 printer complaint was missing lines across the printout then we immediately suspect the printer head, the ribbon, or sometime the mask. This model is one of many dot matrix printers. It has the same fault as all others.

If you replace the printer’s head without checking the mainboard or checking for any short circuits, chances are good that it will soon fail again.

It is wise to check the six printer driver Ics on any printer you come across. The printer head can be replaced or sent to a specialist for refurbishment. The real question is how can we test or check the printer driver ic?s? You can simply remove the mainboard and see six ic’s with the same part number, which is the STA476A.

One of them will shorten the printer head pin if it is shorted. Each printer driver controls four pins so six printer drivers ic would be responsible for 24 pins. It is also known as a 24 pin matrix printer.

To compare the signatures between good and bad ics, I normally use huntron tracker. Comparing the signatures can make it easy to identify the culprit. An analog meter can also be used to do the same. The resistance of each printer driver ic’s leg is compared. If there are any printer driver ic shorts, the meter will register the reading and the needle will kick to the most right.

Sometimes, there could be multiple ics that were shorted. Once you know which ic gave way, solder it and replace it with a brand new one.

You can check the NEC P8000 printer, or any other brand of dot matrix printers by following the above procedure. This will not only save your printer head but also save you money by not having to purchase a new mainboard.

Source: Jestine Yong