LG 49UF680T/Y, Service Manual

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4.3. White Balance Adjustment
4.3.1. Overview
▪ 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) Adjustment condition : normal temperature
1) Surrounding Temperature : 25 °C ± 5 °C
2) Warm-up time: About 5 Min
3) Surrounding Humidity : 20 % ~ 80 %
4.3.2. Equipment
(1) Color Analyzer: CA-210 (LED Module : CH 14)
(2) Adjustment Computer(During auto adj., RS-232C protocol
is needed)
(3) Adjustment Remote control
(4) Video Signal Generator MSPG-925F 720p/216-Gray
(Model: 204, Pattern: 49)
→ Only when internal pattern is not available
•
Color Analyzer Matrix should be calibrated using CS-100.
4.3.3. Equipment connection MAP
4.3.4. Adj. Command (Protocol)
<Command Format>
- LEN: Number of Data Byte to be sent
- CMD: Command
- VAL: FOS Data value
- CS: Checksum of sent data
- A: Acknowledge
Ex) [Send: JA_00_DD] / [Ack: A_00_okDDX]
▪ RS-232C Command used during auto-adjustment.
Ex) wb 00 00 → Begin white balance auto-adj.
wb 00 10 → Gain adj.
ja 00 ff → Adj. data
jb 00 c0
...
...
wb 00 1f → Gain adj. completed
*(wb 00 20(Start), wb 00 2f(end)) → Off-set adj.
wb 00 ff → End white balance auto-adj.
▪ Adj. Map
4.3.5. Adj. method
(1) Auto adj. method
1) Set TV in adj. mode using POWER ON key.
2) Zero calibrate probe then place it on the center of the
Display.
3) Connect Cable.(RS-232C to USB)
4) Select mode in adj. Program and begin adj.
5) When adj. is complete (OK Sign), check adj. status pre
mode. (Warm, Medium, Cool)
6) Remove probe and RS-232C cable to complete adj.
▪ W/B Adj. must begin as start command “wb 00 00” , and
finish as end command “wb 00 ff”, and Adj. offset if need.
(2) Manual adjustment. method
1) Set TV in Adj. mode using POWER ON.
2) Zero Calibrate the probe of Color Analyzer, then place it
on the center of LCD module within 10 cm of the surface.
3) Press ADJ key → EZ adjust using adj. R/C → 7. White-
Balance then press the cursor to the right(key ►).
(When right key(►) is pressed 216 Gray internal pattern
will be displayed)
4) One of R Gain / G Gain / B Gain should be fixed at 192,
and the rest will be lowered to meet the desired value.
5) Adjustment is performed in COOL, MEDIUM, WARM 3
modes of color temperature.
Color Analyzer
Computer
Pattern Generator
RS-232C
RS-232C
RS-232C
Probe
Signal Source
* If TV internal pattern is used, not needed
START 6E A 50 A LEN A 03 A CMD A 00 A VAL A CS STOP
RS-232C COMMAND
[CMD ID DATA]
Explanation
wb 00 00 Begin White Balance adjustment
wb 00 10 Gain adjustment(internal white pattern)
wb 00 1f Gain adjustment completed
wb 00 20 Offset adjustment(internal white pattern)
wb 00 2f Offset adjustment completed
wb 00 ff
End White Balance adjustment
(internal pattern disappears)
Adj. item
Command
(lower case ASCII)
Data Range
(Hex.)
Default
(Decimal)
CMD1 CMD2 MIN MAX
Cool
R Gain j g 00 C0
G Gain j h 00 C0
B Gain j i 00 C0
R Cut
G Cut
B Cut
Medium
R Gain j a 00 C0
G Gain j b 00 C0
B Gain j c 00 C0
R Cut
G Cut
B Cut
Warm
R Gain j d 00 C0
G Gain j e 00 C0
B Gain j f 00 C0
R Cut
G Cut