NEC LCD1550X-BK, Service Manual

Page: 67 / 209

2-12
2.8 Inspection
Unless particularly designated, the performance is confirmed in 2.3 Standard setting state. The display should
be set to the full white pattern with signal generator.
2.8.1 Electric performance
2.8.1.1 Confirming the operation of operation SW
(1) The picture must appear within four seconds after turning power switch ON.
(2) Confirm that Power-On Indicator is lit.
(3) Synchronization must not flow when power switch is turned ON and OFF.
(4) OSM must appear when CONTROL button is pressed.
(5) The setting value must smoothly change and abnormalities such as noise must not occur when (+) / (-) button
is pressed.
(6) Press EXIT button, and confirm that OSM picture disappears.
2.8.1.2 Frequency change speed
Confirm that it does not take so long time to change the picture when frequency is changed. (Within five
seconds)
2.8.1.3 Confirming frequency range (Confirming preset timing)
Confirm that the synchronization is not deviated at the designated preset timing (No. 4, 6, 10 and 14).
2.8.1.4 Confirming automatic adjustment function
Input the confirmation timing with signal generator.
Set the pattern to 1-dot-zigzag-grid with frame. Change the adjustment value of CLOCK intentionally, and
select AUTO ADJUST with OSM. Confirm that the picture is put back to normal when (+) button is pressed so
that AUTO ADJUST can be carried out.
2.8.1.5 Confirming composite sync. signal
Input composite sync. signal (SUN57 listed in 2.11 Timing chart) with signal generator, and set the pattern to
1-dot-zigzag-grid with frame. Start up AUTO ADJUST, and confirm that the picture appears normally.
2.8.1.6 Confirming Sync. On Green signal
Input Sync. On Green signal (Timing No. 19), and set the pattern to 1-dot-zigzag-grid with frame. Start up
AUTO ADJUST, and confirm that the picture appears normally.
2.8.1.7 Confirming digital input
Input timing No. 14 to DVI-D connector with signal generator, and set the pattern to horizontal lamp with frame.
Confirm that the picture appears normally (without out-of-synchronism, picture-short, vertical noise of chromatic
color, dot noise, jitter and gray-scale noise).
2.8.1.8 Confirming D-SUB input connector
Input timing No. 14 to D-SUB connector with signal generator, and set the pattern to 1-dot-zigzag-grid with frame.
Start up AUTO ADJUST, and confirm that the picture appears normally.