If you need cheap ink, sell your updated 8620 and buy an older printer (e.g., Brother) that never uses dynamic security.
Double-click the downloaded firmware .exe and select your printer from the dropdown menu. Click Update . hp officejet pro 8620 firmware downgrade new
Before attempting a downgrade, understand the risks involved: If you need cheap ink, sell your updated
Here is the current community-sourced method for the OfficeJet Pro 8620: If you need cheap ink