In order to play a better role, every use of a roll of ribbon or a roll of heat-sensitive paper to clean the print head. Take off the ring and other hard objects to avoid scratching the print head when cleaning the print head, and pay attention not to damage the print head with grounding metal...
https://www.codewel.com/printhead/tto-104mm-printhead-kf-2004-gm11b.html