I have just been given an HP inkjet cartridge that fits various models but not mine (840C). It's a black cart which seems to be the same size as the empty one currently in the printer but when I put it in the cartridge light flashes. Anybody know why it doesn't work?
There may be some other problems out there in place of Cartridges so you should call a technician for that and as i am using Inkjet Printers for Inkjet Coding bought from "citronix uk" offering Industrial Inkjet Coding.