MAIN BOARD ADJUSTMENTS
The main board setting procedures described in this section guarantee correct setting of the video
unit. It is important to respect the order in which the procedures are listed for best results.
NOTE:
In performing these setting an
electrostatic voltmeter and an electronic voltmeter
must be used. In view of the high voltages being measured, proceed with extreme
caution and take care at all times.
HORIZONTAL HOLD ADJUSTMENT
•
Set PC or signal generator to VGA mode.
•
Connect the TP2 pin on main board to GND with
short clip.
•
Connect the frequency counter between GND and
R776 lead which is adjacent to pulse trans (T901).
•
Adjust the frequency to 31.45 KHz
±
100 Hz.
VERTICAL LINEARITY ADJUSTMENT
•
System Test: 640 BY 480 GRAPHICS, CROSS
HATCH PATTERN.
•
Adjust VR601, so that the vertically linearity should
be best condition.
VERTICAL SIZE ADJUSTMENT
•
System Test: 640 BY 480 GRAPHICS.
•
Set the external V-SIZE VR602 (external VR) at
Center Position.
•
Adjust the V-SIZE VR602 and then the vertical
size should be within 180
±
2 mm.
TP2
R776
Fig. 20-11
Locating of R776
VR602
VR601
Fig. 20-12 Vertical Lineariry and
Vertical Size Adjustment
180mm
Video Unit - Pocket Service Guide
20-8
14" COLOUR DISPLAY UNIT - CDU 1435SE/GS11
