I have an HP8620 OfficeJet Pro that until now has been working perfectly for years. The Yellow cartridge was running low so I changed it for a new one and then was told on the printer's screen it was damaged. I searched online and all I have found is to update firmware (this has been done already and currently up to date). Take the cartridges out and clean the contacts, done. Take out the cartridge holder with power off three times, done. I have purchased a full set of brand new cartridges and replaced all fo them. Still no joy. What is worse is that I can not use the printer at all now to scan even. Can anyone assist me please. With all cartridges in (I have used HP SureSupply app to check authenticity and NEVER used fake or refilled cartridges) the current error message is: "One or more cartridges appear to be damaged. Remove them and replace with new cartridges" Its currently showing Cyan and Yellow to be the problem cartridges, despite both being brand new. Please please please help!