Table of Contents
Advertisement
[CRT Circuit]
3. Cut Off
Adjustment
Set the point of three CATs.
purpose
Symptom when
Monochrome with color tint, incorrect brightness.
incorrectly adjusted
Measuring
Oscilloscope
Instrument
Test Point
Test Pin (TP-G)
External Trigger
-----
Measurement DIV SV
Range
TIM 10)lS
Input Signal
VG-814 (No.18)
Full Black
Input Terminal Mini D-SUB 15 Pin lnpu!Terminal
PCB-CRT (G) (Component side)
TP-BND
..
Ell]
VR6GO
0
GTP-B
PCB-CRT (R) (Component side)
PCB-CRT (B) (Component side)
I
o
I
l
VR~
J
Note :
Perform this adjustment after adjustment 2 (High Voltage Control).
Note :
Perform this adjustment more than
5
minutes after energizing because
the brightness changes after turning on the power.
1. Supply a Full Black signal (No.18).
2. Turn the Screen controls of VA-FOCUS counter-clockwise fully.
Note :
VA-FOCUS is installed at the left bottom of the screen from the front view.
3. Adjust the controls so that the Green light is just visible.
4. Set the User Mode.
®
Press the "PICTURE" button on the remote hand unit to activate the
"CONTRAST" adjustment mode.
(b)
Set the initial data of "CONTRAST'' to"+ 12T'. ("+"button)
Unless any effective buttons are pressed within 6 seconds, the picture
will return to the normal picture.
©
Select the "BRIGHT" adjustment mode in the User Mode.
(Q)
Set the initial data of "BRIGHTNESS" to "0" (Center value).
("+"or"-" button)
5. Turn the Cut Off controls (VR6RO, VR6GO, VR6BO) clockwise fully while
obseNing from the parts side.
6. ObseNe the waveform at the test point (TP-G). (Use TP-GND for GND.)
7. Set to the TEST 1.1.8 mode .
®
Press the "1 ", "1 ", and "8" to activate the TEST 1.1.8 mode immediately
after pressing the "TEST" button.
(b)
Keep pressing the "R/B" button to select the "DAC" adjustment mode.
@ Select "0 SUB-BRIGHT'' ("...a..." or
"T"
button).
(Q)
Adjust "0 SUB-BRIGHT'' so that the cathode voltage is 200V.
("~"or"~"
button)
200V
GND _ _ _ _ _ _ _
J_,__ _____ _
®
Supply a Gray Scale signal (No.17).
CD
Press either of R, G, orB button on VG-814 to make monochrome.
@
Roughly adjust the screen controls so that the most bottom portion of 16-
gradation and the 1 level upper than that will be visible at about the
same luminance or the 1 level upper one wiil be a little more lit.
Note : In case of having difficulties in adjusting equivalently, turn the Cut Off
controls (VR6RO, VR6GO, and VR6BO) counter-clockwise to perform fine
control.
(jJ)
Repeat the step @ in the same manner with the each color except
performed in the step
CD.
CD
After adjustment, press "ENTER" to write the data into memory.
CD
Press the ''TEST'' button to terminate the TEST 1.1.8 mode.
-19-
Advertisement
Table of Contents
