You will need to source an older version (typically versions from 2014 or 2015 are the most "open"). These are often found on community forums or archival sites since HP doesn't host old versions on their official support page.
If you’re frustrated by "Cartridge Problem" messages or "Non-HP Chip" errors, you aren't alone. For many, performing an is the best way to reclaim control over their hardware. The Problem: HP’s "Dynamic Security" hp officejet pro 8620 firmware downgrade better
Ensure the printer is on and connected directly to your computer via USB. You will need to source an older version
Sometimes, new firmware updates introduce bugs or slow down the printer’s interface. Reverting to a "tried and true" version can restore the snappy performance you’re used to. For many, performing an is the best way
The HP OfficeJet Pro 8620 has long been a workhorse for home offices and small businesses. It’s fast, reliable, and produces high-quality prints. However, many users recently found their printers "locked" or refusing to recognize perfectly good ink cartridges. The culprit? An automatic firmware update.
Open the firmware file on your computer. It will look for connected printers. Select your OfficeJet Pro 8620.