Specifications

CAUTION
This voltage adjustment is critical to the life of the
printhead.
DO NOT use this adjustment in an attempt
to increase the printing darkness or burn temperature.
Adjustment Procedure
Calculate the proper Printhead Voltage using the appropriate formula below. The
formula to use depends on the type of Printhead used in the printer. In the formula, R
is the Print Element average resistance value as indicated on a label on the Printhead.
The label can be seen by releasing the Printhead latch, moving the ribbon (if any) to
the side and looking up at the underside of the Printhead.
(The charts in this section may be used instead of the formulas.)
6 dot/mm formula:
8 dot/mm formula:
12 dot/mm formula:
1. Remove the four mounting screws and the Left Side Panel to provide access
to the Main Logic Board.
2. Locate the Head Voltage Adjustment Potentiometer (RV2) below the
transformer and filter capacitors on the Power Supply Board.
3. (105S and 105Se Only) On the Main Logic Board, attach a voltmeter
between test point TP8 and Ground. TP8 is located to the left of the DC
Power Cable Connector J9.
(160S Only) On the Power Supply Board, attach a voltmeter between
the left end of Diode Z3 and ground. Diode Z3 is located just to the right
of potentiometer RV2.
4. Turn the printer ON.
5. Adjust RV2 so the voltmeter reading matches the value determined at the
beginning of this procedure.
6. Turn the printer OFF, disconnect the voltmeter leads, and replace the
printer’s Left Side Panel.
VR=×+0 978 0 48..
VR=×+0 64 0 479..
VR=×+04127 058..
6 Dot/mm Printhead Voltage Table
Ω Volts Ω Volts Ω Volts
315 18 355 19.1 395 20.1
320 18.2 360 19.2 400 20.3
325 18.3 365 19.4 405 20.4
330 18.4 370 19.5 410 20.5
335 18.6 375 19.6 415 20.6
340 18.7 380 19.8 420 20.7
345 18.8 385 19.9 425 20.9
350 19 390 20
S -Series Maintenance Manual: Volume 1 Corrective Maintenance
38452L Rev. 3 Page 5-13