There is a button on the printer. If you don't understand the key, then turn on the printer. After a few seconds, the self-test page will be printed. If there are words, the print head is in good condition, so consider the connection between the printer and the computer host, such as wires and interfaces. If there is no text, there may be something wrong with the machine. Kitchen printer, the line is too long, and it is easy to cause problems such as page drop and blank.