8
4. ADJUSTMENT
4-1 ADJUSTMENT CONDITIONS AND PRECAUTIONS
1.
Approximately 30 minutes should be allowed for warm up before proceeding.
2. Adjustments should be undertaken only on those necessary elements since most of them have been carefully
preset at the factory.
4-2 MAIN ADJUSTMENTS
NO.
FUNCTION LOCATION
DESIGNATION
1.
14.5V ADJ
PCB - MAIN
VR901
2.
B + ADJ
PCB - MAIN
VR902
3.
SCREEN ADJ
FLY BACK TRANS
T402
4.
FOCUS ADJ
FLY BACK TRANS
T402
5.
ABL ADJ
PCB - MAIN
VR701
6.
SUB-BRIGHTNESS ADJ
PCB - MAIN
VR702
-MENU
2
PCB - MAIN
SW103
-UP
PCB - MAIN
SW105
7.
FUNCTION ADJ -DOWN
PCB - MAIN
SW104
-EXIT
1
PCB - MAIN
SW102
4-3 ADJUSTMENT METHOD
1. 14.5V, B + & HV voltage adjustment and hold down circuit confirmation:
A. Chrome-2000 Signal generator or PC equivalent set mode 1, VGA 640
X
480 pattern 1.0 .
B. Connect a DC Volt meter between TP901 or D922 cathode and ground, then adjust VR901 to be 15VDC.
C. Connect a DC Volt meter between TP902 or D925 cathode and ground, then adjust VR902 to be
49VDC(B+).
D. Connect a DC Volt meter between TP701(G1) and ground, Brightness set to max. Then adjust VR702 to
be -35 VDC.
E. Connect a 22k
Ω
resistor in parallel with R419 to increase the HV, the hold down circuit will operate and
the display will disappear. Then disconnect this resistor to bring the unit to normal condition.
2. Factory preset Timings Adjustment:
A. Press
MENU Key
to show
OSD
window press
Up
or
Down Key
to switch the functional controls.
B. Press the
Up
Key to select the "
ZOOM
" function, then press the
MENU
Key. While do not release the
MENU
Key until the
OSD
window changed to the Factory preset window.
C. The Factory preset window contains the following functional controls. Select one of the control. Then press
the
Up/Down
Key to adjust it's value for the optimum picture.
