Adjustment; Adjustment Conditions And Precautions; Main Adjustments; Adjustment Method - ViewSonic Q51 series Service Manual

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
1. 14.5V ADJ
2. B + ADJ
3. SCREEN ADJ
4. FOCUS ADJ
5. FUNCTION ADJ

4. 3 ADJUSTMENT METHOD

14.5V, B + & HV voltage adjustment:
A. Chroma-2000 Signal generator or PC equivalent set mode2:, VGA 640X480 pattern 1.0.
B. Connect a DC Volt meter between TP901 (or the equivalent point) and ground, then adjust VR901 to be 14.2VDC.
C. Connect a DC Volt meter between TP902 (or the equivalent point) and ground, then adjust VR902 to be 85 VDC.
Factory preset Timings Adjustment:
A. Press Encoder control Key to show OSD window then press again to switch the functional controls.
B. Select to the "ZOOM" function, then press the button while does not release until the OSD window changed to the
Factory preset window.
C. The Factory preset window contains the following functional controls. Select one of the controls to adjust its value
for the optimum picture.
White Balance adjustment(Bias ,Gain, ABL):
A. Bias (Raster luminance and cut off ) adjustment:
(a) Set mode 5 800×600 Fh: 53KHz full white pattern.
(b) To make the adjustment condition is under the Factory preset window.
Same as step 2-C.
(c) Warm up more than 20 minutes.
(d) Change pattern to mode 5 Raster pattern (only Raster, no video), Brightness
set to min., G-Bias
±0.2cd/m², x= 265 ± 5, y= 290 ± 5.
(e) Raster cut off adjustment: adjustment the Brightness makes the Y=0.08±0.02cd/m², then save the adjustment
data to 9300 and 6500.
-MENU
-UP
-DOWN
-EXIT
40, then adjust FBT screen VR. R-Bias
LOCATION
PCB - MAIN
PCB - MAIN
FLY BACK TRANS
FLY BACK TRANS
PCB - MAIN
PCB - MAIN
PCB - MAIN
PCB - MAIN
8
DESIGNATION
VR901
VR902
T402
T402
SW102
SW103
SW104
SW105
set to maximum. Contrast
. B-Bias to make Y= 3.5