1. If the problem still exists, you can resume the factory operation. On the printer panel, press ok to enter, press arrow keys to find service, press ok to enter, press arrow keys to find restore defaults, and then press ok.
2. If the above steps can't solve the problem, see if the LCD screen of the printer is ready. If so, consider upgrading the firmware. However, during the firmware upgrade, no one can use the printer. If the upgrade fails, the hardware may be damaged. It is recommended to contact HP personnel to lead the operation or directly contact the local maintenance center to help upgrade the firmware.