9-20
Phaser 440 Color Printer
9
Checks and Adjustments
VH current compensation adjustment
This adjustment sets the rate of compensation for the power supply to adjust the
VH voltage to changes in the total current drawn by the thermal head elements
as they individually conduct current.
1.
Turn off the printer. Ensure that the paper tray is filled with Letter
Extra paper.
2.
Remove the top rear cabinet panel to access the engine control board
and the left side cabinet panel to access the VH current compensation
adjust potentiometer (behind the drum idler pulley). Refer to the
Chapter 8 topic “Printer cabinet panels” on page 8-4.
3.
Press and hold the
TEST
button and turn on the printer. Release the
TEST
button. The printer is now in service mode.
4.
Set Dip Switch 4 and 7 on to select Test Pattern 9. Toggle DIP Switch
1-8 to start the test print printing.
Note
The gray field in the test prints will appear “plum”-colored.
5.
Examine the test print. Look to see that there is no color (ghosting)
appearing in the gray areas bordering to the right end of the cyan,
magenta and yellow bars. This is illustrated in Figure 9-3. If no color
is apparent then the current compensation is good, go to Step 8. If
color appears in the gray, continue with the next step.