If downgrading firmware fails or you cannot find old firmware, you can reset the chip itself using a (available on eBay/Amazon for $10–20).
If your printer is heavily locked or failing to accept normal transfers, you may need to force flash mode. Turn off the printer. Hold down the Print Screen button while turning the printer back on via the Power button. Release both buttons when the LED indicator lights up. If downgrading firmware fails or you cannot find
After the firmware is applied and the chip is covered, the toner level should show as 100% every time you restart the printer. Critical Warnings Hold down the Print Screen button while turning
If you’d like, I can also provide a for the downgrade process, or help you locate the correct firmware version number based on your printer’s exact model and region. Critical Warnings If you’d like, I can also