A critical hardware risk exists when downgrading. If a user installed a third-party cartridge while on new firmware, the printer may have written data to the cartridge chip identifying it as "used in a locked printer." Downgrading the printer firmware might not unlock these cartridges, as the lock status is stored on the cartridge's own IC. The printer may continue to reject them, rendering the downgrade futile for that specific set of consumables.

Press the four times consecutively (even if it is unlit). The hidden Support Menu will appear on the LCD screen. Use the navigation arrows to find Reset Menu and press OK. Select Semi-Full Reset or Full Reset and confirm.

and R1640A are common targets for restoration.

On the printer control panel, go to and set it to Manual or Off . Download Older Firmware Visit the HP Support website and enter your model.

How to Downgrade HP OfficeJet Pro 8620 Firmware: A Step-by-Step Guide Why Downgrade? hp officejet pro 8620 firmware downgrade

Look for firmware version FDP1HA1416AR or older.

The bad news is that downgrading the firmware on your HP OfficeJet Pro 8620 is officially by HP. Multiple HP support agents have stated that once your printer is updated to a newer firmware version, it's designed to prevent the installation of any older firmware packages. This means that even if you have a legitimate HP firmware file, the printer will likely reject it.

Open this file in Notepad, locate the restriction lines (such as VerifyROMID=1 or CheckVersion=1 ), change their values from 1 to 0 , and save the file. Step 4: Flash the Downgraded Firmware

Ultimate Guide: HP OfficeJet Pro 8620 Firmware Downgrade to Use Third-Party Ink A critical hardware risk exists when downgrading

On the printer screen, navigate to Settings > Printer Maintenance > Update Printer > Manage Updates . Ensure Allow Downgrade is set to Yes .

A common issue is that users might find a newer firmware file (e.g., OJ8620_1910A.exe ) on the HP website, only to find it's "Not Applicable" to their printer that is already running a different version (e.g., FDP1CN2022AR ). A full factory reset will also not restore an older firmware version; it only resets your settings to their defaults.

The HP OfficeJet Pro 8620 is a powerful machine crippled by aggressive firmware policies. Downgrading to version 1738A or earlier can restore your ability to use affordable third-party ink, but the process is technically demanding and increasingly locked down by HP.

Find your printer's IP address from the network settings on the screen. Type that IP address into any web browser on your computer. Go to the or Web Services tab. Locate Product Updates or Firmware Updates . Uncheck the box for automatic updates and save the changes. Troubleshooting Common Errors The Update Utility Says "Not Applicable" or Greyed Out Press the four times consecutively (even if it is unlit)

Since HP does not officially provide old firmware, users often find older .exe or .rfu packages on reputable third-party sites or community forums .

Once your file is ready and your printer is connected via USB, follow these execution steps:

Run the modified firmware executable or the main flashing utility ( HPFWUpd.exe ) from your extracted folder.