OKIDATA Pacemark 3410 Service Handbook page 158

Procedure
NOTE:
The printhead gap must measure .014 +/- .002 inches (0.35 +/- 0.05 millimeters).
Setup Phase (Steps 1 - 6)
1. Remove the ribbon cartridge and ribbon guide (3.2.01).
2. Remove the ribbon protector (3.2.02).
3. Remove the upper cover (3.2.03).
4. Set the printhead gap lever to position 1.
5. Set the release lever to the CUT SHEET ("OPEN") position.
6. Loosen the left and right eccentric collar mounting screws.
Printhead Gap Modification Phase (Steps 7 - 9)
7. Move the printhead to the left side of the platen.
8. Rotate the left eccentric collar until the correct gap is obtained.
9. Move the printhead to the right side of the platen.
Parallel Adjustment Phase (Steps 10 - 12)
10. Rotate the right eccentric collar until the correct gap is obtained.
11. Move the printhead to the left side of the platen.
12. Recheck the gap, rotating the left eccentric collar as necessary.
Check Phase (Steps 13 - 16)
13. Move the printhead to the right side of the platen.
14. Check the gap, rotating the right eccentric collar as necessary.
15. Repeat Steps 11 - 14 until the the correct gap is obtained at each side of the platen.
16. Move the printhead to the center of the platen and check the gap.
17. When the correct gap has been attained, tighten the left and right eccentric collar
mounting screws.
18. Install the upper cover, the ribbon protector, ribbon guide and the ribbon cartridge.
NOTE:
When installing the printhead, push it towards the platen. This ensures a correct fit
between the printhead and stopper. Then, tighten the printhead screws.
Maintenance 3 - 72 Pacemark 3410 Service Handbook