White Balance (Ntsc); White Balance (Hd) - Mitsubishi Electric WT-42311 Service Manual

[CRT Circuit]

5. White Balance (NTSC)

Measuring
DC Voltmeter
Instrument
Test Point
------
Ext. Trigger ------
Measuring
------
Range
Input Signal
NTSC White Raster
Input Terminal
RF or Video
CIRCUIT ADJUST MODE
Activate ........ MENU-2-2-5-7
Function .................AUDIO
Item No. .................VIDEO
Adjust Data ...........ADJUST
Save Data .... .........ENTER
Exit ..............MENU (twice)
[CRT Circuit]

6. White Balance (HD)

Measuring
-----
Instrument
Test Point -----
------
Ext. Trigger
Measuring
-----
Range
Input Signal
HD White Raster
Input Terminal
DTV Inputs
CIRCUIT ADJUST MODE
Activate ........ MENU-2-2-5-7
Function .................AUDIO
Item No. .................VIDEO
Adjust Data ...........ADJUST
Save Data .... .........ENTER
Exit ..............MENU (twice)
MODEL: WT-42311 / WT-A42
Purpose:
To set the CRTs white level in the NTSC mode.
Symptom:
Monochrome has a color tint.
Note: Use the "FORMAT" button to activate the Expand mode (full screen).
1. Supply a full White Raster Signal
2. Activate the Service Mode, Video Chroma Function.
3. Set the data for Item "19 COL" to 0.
4. Adjust Items "4 RDRH" and "6 BDRH" for optimum white at the center of
the screen.
5. Reduce the input luminance level to 25%.
6. Adjust Items "7 CTRH" and "9 CTBH" for optimum white.
7. Insert a Milliammeter in series with each CRT Cathode. The maximum
allowable current for each CRT is given in the table below.
8. Set the white raster to 100% and adjust Items "10 RDRL" and "12 BDRL" for
optimum white at the center of the screen.
9. Reduce the luminance level to 25%.
10. Adjust Item "13 CTRL" and "15 CTBL" for optimum white.
11. Set the data for Item "19 COL" back to 31.
Maximum CRT Current
CRT
RED
GREEN
BLUE
To set the CRTs white level in the HD mode.
Purpose
Monchrome pictures have a color tint.
Symptom:
1. Supply an HD Full White Raster signal to the DTV Inputs.
2. Select the DTV Inputs (Input button)
3. Activate the Adjustment mode, Video Chroma Function.
4. Set Item "19 COL" to 0.
5. Adjust Items "4 RDRH" and "6 BDRH" for optimum white at the center of the
screen.
6. Reduce the input signal luminance to 25%.
7. Adjust Items "7 CTRH" and "9 CTBH" for optimum white.
8. Set the white raster to 100% and adjust Items "10 RDRL" and "12 BDRL" for
optimum white at the center of the screen.
9. Reduce the luminance level to 25%.
10. Adjust Item "13 CTRL" and "15 CTBL" for optimum white.
11. Set the data for Item "19 COL" back to 31.
NOTE: After completing HD White Balance, set the corresponding adjustment items
in 480p to the same data values
Page 27
CURRENT
580 uA
580 uA
580 uA