LG 43LF513A-TA, Service Manual

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Only for training and service purposes
5. White Balance Adjustment
5.1. Overview
5.1.1. W/B adj. Objective & How-it-works
(1) Objective: To reduce each Panel’s W/B deviation
(2) How-it-works: When R/G/B gain in the OSD is at 192, it
means the panel is at its Full Dynamic Range. In order to
prevent saturation of Full Dynamic range and data, one of
R/G/B is fixed at 192, and the other two is lowered to find
the desired value.
(3) Adj. condition: normal temperature
1) Surrounding Temperature: 25 °C ± 5 °C
2) Warm-up time: About 5 Min◦
3) Surrounding Humidity: 20% ~ 80%
4) Before White balance adjustment, Keep power on
status, don’t power off.
5.1.2. Adj. condition and cautionary items
(1) Lighting condition in surrounding area surrounding lighting
should be lower 10 lux.
Try to isolate adj. area into dark surrounding.
(2) Probe location: Color Analyzer(CA-210) probe should be
within 10 cm and perpendicular of the module surface.
(80°~ 100°)
(3) Aging time
1) After Aging Start, Keep the Power ON status during 5
Minutes.
2) In case of LCD, Back-light on should be checked using
no signal or Full-white pattern.
5.2. Equipment
(1) Color Analyzer: CA-210 (NCG: CH 9 / WCG: CH12 / LED:
CH14)
(2) Adj. Computer(During auto adj., RS-232C protocol is needed)
(3) Adjust Remote control
(4) Video Signal Generator MSPG-925F 720p/204-Gray
(Model: 217, Pattern: 49)
* Color Analyzer Matrix should be calibrated using CS-1000.
5.3. Equipment connection
** RS-232C Connection Method.
LB56G/LB56H → RGB cable or 3P H/P cable → UART Jig
→ RS232C cable and USB AM-BM cable → PC
5.4. Adjustment Command (Protocol)
(1) RS-232C Command used during auto-adj.
(2) Adjustment Map
5.5. Adjustment method
5.5.1. Auto WB calibration
(1) Set TV in ADJ mode using P-Only key(or POWER ON key).
(2) Place optical probe on the center of the display.
- It need to check probe condition of zero calibration before
adjustment.
(3) Connect RS-232C Cable
(4) Select mode in ADJ Program and begin a adjustment.
(5) When WB adjustment is completed with OK message, check
adjustment status of pre-set mode.(Cool, Medium, Warm)
(6) Remove probe and RS-232C cable.
▪ W/B Adj. must begin as start command “wb 00 00” , and
finish as end command “wb 00 ff”, and Adj. offset if need.
5.5.2. LED White balance table
- If Model is Polaris Model, G-gain fix is applied.
(1) Cool Mode
1) Purpose : Especially G-gain fix adjust leads to the
luminance enhancement. Adjust the color temperature
to reduce the deviation of the module color temperature.
2) Principle: To adjust the white balance without the saturation,
- Adjust the G gain more than 172 (If R gain or G gain is
more than 255, G gain can adjust less than 172) and
change the others(R/B Gain).(20LB45X model)
- Fix the G gain to 172(default data) and change the
others(R/B Gain).(over 22inch model)
3) Adjustment mode : mode - Cool
Color Analyzer
Computer
Pattern Generator
RS-232C
RS-232C
RS-232C
Probe
Signal Source
* If TV internal pattern is used, not needed
RS-232C COMMAND
Explanation
CMD DATA ID
wb 00 00 Begin White Balance adjustment
wb 00 ff
End White Balance adjustment
(internal pattern disappears)
Adj. item
Command
(lower caseASCII)
Data Range
(Hex.)
Default
(Decimal)
CMD1 CMD2 MIN MAX
Cool
R Gain j g 00 C0 172
G Gain j h 00 C0 192
B Gain j i 00 C0 192
R Cut 64
G Cut 64
B Cut 64
Medium
R Gain j a 00 C0 192
G Gain j b 00 C0 192
B Gain j c 00 C0 192
R Cut 64
G Cut 64
B Cut 64
Warm
R Gain j d 00 C0 192
G Gain j e 00 C0 192
B Gain j f 00 C0 192
R Cut 64
G Cut 64
B Cut 64