In every ink-jet printer catridge there is a circuit board on flexible media connected with a device which through the ink on the paper. I want to know what and how exactly the device do and how can it be tested for working. I have also tried to repair a JAM Catridge with hot water and petrol. is there another way to repair it. Thanks
Some ink cartridges like HP have the print head built in, and on those there's many contact points but cartridges without print heads built in often use "Prom counters" that prevent printing after so many pages printed regardless of the amount of ink remaining in the cartridge. For these you can purchase on ebay a reset tool to reset the prom chip. Carefully clean built-in print heads with either deionized water or 90+ % Isopropyl if water won't work, try using a non lint qtip and be very gentle.