Black Level - Mitsubishi WS-48315 Service Manual

[Video Circuit]

7. Black Level

Measuring
Instrument
Test Point
Ext. Trigger
Measuring
Range
Input Signal
Input Terminal
CIRCUIT ADJUST MODE
Activate ........ MENU-0-3-5-7
Function .................AUDIO
Item No. .................VIDEO
Adjust Data ...........ADJUST
Save Data .... .........ENTER
Exit ..............MENU (twice)
[Video Circuit]
8. Sub Contrast
Measuring
Instrument
Test Point
Ext. Trigger
Measuring
Range
Input Signal
Input Terminal
CIRCUIT ADJUST MODE
Activate ........ MENU-0-3-5-7
Function .................AUDIO
Item No. .................VIDEO
Adjust Data ...........ADJUST
Save Data .... .........ENTER
Exit ..............MENU (twice)
Downloaded from www.Manualslib.com
MODELS: WS-48315 / WS-55315 / WS-65315
Purpose:
Symptom:
-----
1. Supply a Monoscope signal to a Video Input.
2. Activate the Adjust Mode, Video Chroma Function.
-----
3. Adjust Item "2 SBRT" so the 0% and 10% black levels on the gradation scale
------
4. Press ENTER to save data.
------
7. Exit the Service Mode.
Monoscope
NOTE: Item 2 SBRT should be no more than "21".
Video Input
40% 30% 20% 10%
50% 0%
60% 70% 80% 90%
GRADATION SCALE
Purpose:
Symptom:
Note: Activate the Expand mode (full screen).
DC ma meter
1. Supply a Grayscale signal to a RF Input.
DT connector pins 7 & 8
2. Activate the Adjust Mode, Video Chroma Function.
3. Select Item "1 SCT", signal level automatically reduces.
------
4. Connect a 3ma DC meter between DT connector pins 7 and 8. Positive lead to
-----
5. Adjust Item "1 SCT" for the current given in the table below.
6. Remove the meter.
Grayscale
7. Press "ENTER" to save data.
RF Input
8. Exit the Service Mode.
Sub Contrast Current Alignment
WS-48315 / WS-55315
520 ±10ua
manuals search engine
To set the black level of the picture.
Excess or insufficient brightness.
are the same.
0% 0%
To set overall beam current to its' optimum level.
Excess or insufficient contrast.
pin 7.
WS-65315
550 ±10ua
Page 33