Compuprint SP40 plus - Manual (Page 12)

User Manual
MAN10239-01 7
8.
The printer is now ready to install the ribbon
cartridge.
9.
Turn the tension knob in the direction
of the arrow to tighten the ribbon.
10.
Insert the upper cartridge pins onto the
corresponding grooves on both sides of the upper
mechanical frame.
11. Then push the lower cartridge pins into
the corresponding lower grooves on both
sides of the upper mechanical frame until it clicks
into place.