Facit 4431 Service Instruction page 28

28
e VERTICAL FREQUENCY
The Vertical frequency should by adjusted so
that the potentiometer is positioned half
way between the points there the picture
starts to roll.
Adjustment instructions:
In SET-UP mode B, set the terminal to 50Hz.
Move the Vertical Frequency adjustment poten-
tiometer CCW (counter clockwise) until the
display starts to roll, note the potentiome-
ter position and change the terminal to 60Hz
(in SET-UP B mode) now turn the potentiome-
ter CW (clockwise) until the display starts
to roll, note this position and adjust the
potentiometer so that it is positioned half
way between the points there the picture
starts to roll.
• HORIZONTAL FREQUENCY CONTROL
Adjust the potentiometer so that it is posi-
tioned half way between the points there the
picture starts to roll.
• HORIZONTAL PHASE CONTROL
In 132 column mode, adjust the potentiometer
CW and CCW so that the display folds over
the margins, note these positions and adjust
the potentiometer half way between these
points.
e BRIGHTNESS CONTROL
SET UP A mode.
First reset the terminal to delivery status
by typing (SHIFT) and D simultaneously, then
adjust the brightness potentiometer so that
low intensity portion of the display in SET
UP A mode are just visiable.
• HORIZONTAL WIDHT CONTROL
This control is to adjust the horizontal
widht of the display. Adjust the horizontal
widht to 8" +/- 0.6".
t
CENTERING
The yoke rings are used for centering the
display area on the screen of the CRT.
e PINCUSHION
Rubber magnets to be used to correct the con-
cave lines at outer edges of the display
pattern.
HORIZONTAL
WIDTH
9.7 POWER SUPPLY
BRIGHTNESS
The power supply output voltages are adjustable
by the power supply potentiometer located on
the power supply circuit board.
Use +12 Volt to the monitor at Main Logic Board
connector X3 Pin 4,5 as reference when measu-
ring (+12V +/- 0.6V).
VOLTAGE ADJUSTMENT POT.
117/220V AC CONVERSION JUMPER.