The thermal receipt printer prints effect with a sense of compression

Cause of issue:
a. The paper is not transported smoothly.
b. There is a problem with the paper feed motor.
c. The paper feed roller is not clean.
d. The paper feed roller does not rotate smoothly.
e. The printer feed speed is not appropriate.
f. The PC board is faulty.

Elimination method:
a. Check if the width of the paper is too wide
b. Replace the paper feed motor.
c. Clean the paper feed roller.
d. Clean and lubricate the paper feed roller.
e. Replace the mechanical module of the entire printer.
f. Replace the PC board.