1. Check whether the touch screen wiring is loose, and reconnect the touch screen wiring
2. Re-update the firmware：Copy the ".bin" file in the link below to the root directory of the U disk, and do not create any folders in the U disk. Then restart the printer.
https://drive.google.com/file/d/1FeKI977a6CIvNuU0H2eQUKQcPKKnTLkf/view?usp=drive_link