First of all, you need to soak dried paint. If your printer has a removable head, then you can take a carriage to the middle of the printer, put them under a saucer with warm water, and put a rag so that it touches the print surface of the heads. Leave it for 3-4 hours.
If you have a printer with the heads built into the cartridges, you can simply remove them and put them in a saucer with warm water so that the head was immersed in water only 1.5-2 mm.
To heads printers brands HP, you can also add a few drops of ammonia in water will accelerate cleaning.
Then you need to re-make the refill cartridges and run a standard cleaning process of the cartridges. There are also sprays of factory production is intended for the same purpose, but they are effective only in the initial stages of contamination of the printheads.
If to clean the printer head failed because of too much pollution its nozzles, it is necessary to pump out the contaminated cartridges paint and replace it with distilled water. Next, to load the surface of the print heads in warm water.
Create a drawing and fill it with solid black. Further to unclog the printer head, it is necessary every 1.5-2 hours print out the prepared pattern on the entire page. So is cleaning the print nozzles, and you can control the cleaning process. It can be considered as completed, if the entire page is evenly wet.
Then set the printer to maximum quality and brightness of the print, and print again 3-4 times this figure.
Remove from the cartridge the residual water with a syringe. Then, you should refill cartridges and make the factory clean and align cartridges. If the print quality is satisfactory, then re-perenapravlenie cartridges and re-set the printer.