I have a Canon Pixma MP 500. I inserted a new magenta cartridge and when I try to print it says it does not recognize the cartridge. I thought that the cartridge was bad so I took it back and got another one. When I insert the cartridge it does not light up and I keep getting the message that it can't be recognized. What do I do?

CLI-8M and other cartridges also have a chip. Printer reads the content of the chip before printing. What cartridge have you put in, original Canon's or compatible one?? Check the metal contacts in the cartridge nest, they all should look the same, check if there is any damage to the contacts. If the printer gives this message it cannot read the chip content.