If the software downgrade fails, the "new" solution the repair shops are using is . On eBay, you can buy "pre-downgraded" logic boards for the 8620 for about $40. Swapping the mainboard resets the firmware to the factory version that shipped with the board (usually a 2018 version). This is a 30-minute screwdriver job. It is the only 100% guaranteed method left.
HP OfficeJet Pro 8620 Firmware Downgrade: New Methods & Solutions (2026 Guide)
Turn it off for 5 minutes, then back on. If it fails, you may need to try the Ncat method again. hp officejet pro 8620 firmware downgrade new
As of March 2025, . The remote downgrade exploit via telnet (used in 2022-2023) is patched. The USB recovery method is the only active vector.
"So, you broke my printer on purpose?" Elias asked. If the software downgrade fails, the "new" solution
Find a secure download link for an earlier, known-good firmware version for the 8620.
To downgrade your HP OfficeJet Pro 8620 Go to product viewer dialog for this item. This is a 30-minute screwdriver job
If you are looking for a downgrade, you already know why. HP’s infamous feature acts like a bouncer at a nightclub. It scans your ink cartridges. If they aren't HP-branded (or if they are older, "remanufactured" chips), the printer refuses to print. It turns your $200 printer into a paperweight.
The printer may restart during this process. Do not intervene.
NEVER turn off the printer during the downgrade process. This can permanently damage the printer (brick it).
If you do not turn off automatic updates, your printer will simply download the restrictive firmware again within a few days.