New printer head, or the printer head is too close to the platen. Should adjust the distance between the printer head and the platen.
The print head is broken. Replace the print head.
A.The ribbon guide wasn't taken out from the cartridge. Should take it out and roll the tape for several rounds until it's normal.
B.Reverse the gear wheels, roll the tape in a right direction, after several circles until it becomes normal, the ribbon can be installed.
