1. Zebra® 105SL™ * Removing and Installing Printhead
Calibrating Darkness Setting
Print Quality Adjustments

2. Removing the Printhead
Turn the power switch off and disconnect both the power cord and printer communications cable.
Open Cover.
Remove media and ribbon (if applicable).
Unscrew Printhead mounting screw with flat-head screwdriver.

3. Removing the printhead
1. Open Printhead Lever
Printhead Lever
*Make sure you are appropriately grounded using proper anti-static procedures.
Removing the printhead

4. Right Printhead Assembly Cable
1. Holding the Printhead, carefully disconnect the left Printhead Assembly
cable, then the right Printhead Assembly cable from the back of the Printhead.
2. Remove the Printhead.
Right Printhead Assembly Cable
Left Printhead
Assembly Cable

5. Installing the Printhead
Turn the power switch off and disconnect both the power cord and the printer communications cable.
Open the side cover.

6. Right Printhead Assembly Cable Left Printhead Assembly Cable
Carefully position the new Printhead under the Printhead mounting bracket and connect both Printhead cables into the appropriate ports.
Right Printhead Assembly Cable
Left Printhead Assembly Cable

7. Alignment Posts on Mounting Bracket
Position the alignment slots in the new Printhead with the alignment posts on the bottom of the mounting bracket. You should hear a “clicking sound” which signifies that the Printhead is securely in place. Tuck the Printhead cables behind the Printhead.
Alignment Posts on Mounting Bracket
Alignment slots
In Printhead

8. Clean the Printhead using an alcohol
swab, removing dirt or oil that may have
been deposited during installation.
Alcohol swab
Print line

9. Reinstall media and ribbon (if applicable).

10. Printhead Mounting Screw
Lower the Printhead Assembly.
Close the Printhead lever and check for proper alignment.
Close the side cover.
Connect the power cord and printer communications cable.
Turn power on.
Printhead Mounting Screw
If the print line is not parallel with the platen roller, check that the Printhead Assembly guides fit snug into the Printhead slots.

11. Printhead Position Adjustment
Loosen the four top screws, found at the rear of the Printhead Assembly (do not remove).
If print is lighter toward one side of the label and Printhead has been correctly installed, perform the Printhead Position Adjustment.
Top screws
Printhead Position Adjustment

12. 1. Adjust the two gold hex nuts found at the rear of the Printhead Assembly (as viewed from the rear of the Printer). Adjusting the gold hex nuts clockwise will move the Printhead toward the back. Making 1/8 turns will have a noticeable affect in the print quality.
2. Adjust the hex nut on the same side as the lighter print. Adjust in one direction, printing a test label after each adjustment. If print begins to darken, continue until desired darkness is achieved. If print becomes lighter, adjust the hex nut the opposite direction until desired print darkness is reached.
Gold hex nuts

13. Toggle Position Adjustment
Locking nut
Loosen locking nut so the toggle can slide freely.
Position the toggle so it distributes even
pressure across entire label.
Upper knurled nut
Adjusting nut
Threads showing underneath the Adjusting nut

14. Printhead Pressure Adjustment
Too much pressure applied to the toggles will shorten the life of the Printhead. Choose the lowest pressure that produces the desired print quality, maximizing Printhead life.
Printhead Pressure Adjustment
Print several test labels at 2 ips by pressing SETUP/EXIT, scroll until Print Speed is displayed and select 2 ips.
During the test printing, use the LCD panel to lower the darkness setting until the labels print gray instead of black.
3. On the toggle assembly, loosen the Upper knurled nut found above the adjusting nut.
4. Looking down at the printer, use the adjusting nut to increase (clockwise) or decrease (counter-clockwise) pressure until darkness is uniform across label.
5. Once uniformity is achieved, adjust the darkness level on the LCD until printing is clear.
6. Tighten the Upper knurled nut against the Adjusting nut.

15. Perform this adjustment to help achieve even pressure
Wear Plate Adjustment
Wear Plate Adjustment
Run several test labels at 2 ips.
During label testing, use the LCD panel to lower the darkness setting until the labels print gray instead of black.
Use a 7/64 hex wrench to loosen the two hex nuts attached to wear plate.
Perform this adjustment to help achieve even pressure
Silver Adjustment Knob
Wear Plate
Two hex nuts

16. Silver Adjustment Knob
For even pressure across width of label, adjust the Silver Adjustment Knob with your hand or with a 7/16 wrench.
Turning the Silver Adjustment Knob clockwise will increase pressure on the left side of label (as viewed from front of printer). Adjusting it counter-clockwise will increase pressure on right side of label.
When gray print is even across label, tighten the two hex nuts to secure wear plate in place.
On the LCD, increase darkness setting to achieve desired print quality.
Silver Adjustment Knob
Wear Plate
Two hex nuts

17. Calibrating the Darkness
After the printer is turned on and self power test is completed, press the SETUP/EXIT button.
If the LCD does not display DARKNESS, scroll forward or backward using the INCREMENT buttons (+ or -).
Once DARKNESS is displayed on the LCD, press the INCREMENT buttons to increase or decrease the DARKNESS value.
After printing a successful label at the desired darkness level, press the SETUP/EXIT button twice to save the changes and exit the setup mode.

18. Zebra is a registered trademark of ZIH Corp
Zebra is a registered trademark of ZIH Corp. All other trademarks are the property of their respective owners.
(*) Contents Subject to Change Without Notice Doc. No. Z105SL-Instructions_082405