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MODELS: VS-45609 / VS-50609 / VS-55609 / VS-60609 / VS-60719 / VS-70709
[CRT Circuit]
7. CRT Cutoff
Measuring
Oscilloscope
Instrument
Test Point
TP6R, TP6G, TP6B
Ext. Trigger
------
Measuring
50V per division/ 2 msec
Range
Input Signal
None
Input Terminal
Video Input
SERVICE MODE
Activate ........ MENU-0-1-5-7
Function .................AUDIO
Item No. .................VIDEO
Adjust Data ...........ADJUST
Save Data .... .........ENTER
Exit ..............MENU (twice)
[CRT Circuit]
8. White Balance
(High Color Temperature)
Measuring
DC Meter
Instrument
Test Point
R6G30, R6B30
------
Ext. Trigger
Measuring
-------
Range
Input Signal
Full White Raster
Video Input
Input Terminal
SERVICE MODE
Activate ........ MENU-0-1-5-7
Function .................AUDIO
Item No. .................VIDEO
Adjust Data ...........ADJUST
Save Data .... .........ENTER
Exit ..............MENU (twice)
Purpose:
To set the cutoff point for all three CRTs.
Symptom:
Monchrome has a color tint, or incorrect brightness.
1. Select an External Input with no signal.
2. Enter the Service Mode, VCJ Function.
3. Set the data to the values given for the Items listed in the Table.
4. Connect the oscilloscope to TP6R.
5. Adjust the Red SCREEN VR so the black level is 200V, as shown below, or to
206 ±1VDC using a DC Voltmeter.
6. Repeat Steps 4 and 5 to set the Blue and Green SCREEN VRs, using TP6G
and TP6B.
Note: The White Balance Adjustment must be performed after Cutoff Adjustment.
To set the CRTs white level
Purpose:
Monchrome has a color tint.
Symptom:
Note: This adjustment must be performed after the CRT Cutoff and Focus
Adjustments.
High Color Temperature White Balance
1. Supply a Full White Raster signal to the Video Input.
2. Enter the Service Mode, VCJ Function.
3. Adjust Items "11 RDRH" and "13 BDRH" for optimum white at the center of the
screen.
Note: If the Cutoff level changes during the adjustment, use Items "8 CTRH"
and "10 CTBH" to touch up the Cutoff level. Then readjust "RDRH" and
"BDRH".
4. Save data and exit the Service Mode.
5. Use a DC Current Meter to measure each CRT's current.
• The meters internal resistance must be less than 30 Ohms.
• Lead length must be less than 30 CM.
6. Connect the meter, in sequence, across each of the following resistors to read
the current for that respective CRT.
• Green CRT ... across R6G30
• Blue CRT ...... across R6B30
7. The Green and Blue CRT current must not exceed the values given in Table 1.
Maximun CRT Current
CRT
Green
Blue
Page 31
VCJ Function
ITEM
ABBR.
7
BRTH
8
CTRH
9
CTGH
10
CTBH
CURRENT
580 ua
530 ua
Table 1
DATA
31
7
10
7
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