LG 42LY770M, Service Manual

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Only for training and service purposes
5. Final Assembly Adjustment
5.1. White Balance Adjustment
5.1.1. Overview
5.1.1.1. 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
- Surrounding Temperature: 25±5 ºC
- Warm-up time: About 5 Min
- Surrounding Humidity: 20% ~ 80%
- Before White balance adjustment, Keep power on status,
don’t power off
5.1.1.2. 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 10cm and perpendicular of the module surface
(80°~ 100°)
(3) Aging time
- After Aging Start, Keep the Power ON status during 5
Minutes.
- In case of LCD, Back-light on should be checked using no
signal or Full-white pattern.
5.1.2. 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 Remocon
(4) Video Signal Generator MSPG-925F 720p/204-Gray
(Model:217, Pattern:49)
→ Only when internal pattern is not available
※
Color Analyzer Matrix should be calibrated using
CS-1000
5.1.3. Equipment connection
5.1.4. Adjustment Command (Protocol)
(1) RS-232C Command used during auto-adj
(2) Adjustment Map
5.1.5. Adjustment method
5.1.5.1. 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.
5.1.5.2. Manual adj. 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 10cm of the surface.
(3) Press ADJ key -> EZ adjust using adj. R/C -> 6. White-
Balance then press the cursor to the right (KEY►).
(When KEY(►) is pressed 204 Gray(80IRE) internal
pattern will be displayed)
(4) Adjust Cool modes
1) Fix the one of R/G/B gain to 192 (default data) and
decrease the others. ( If G gain is adjusted over 172 and
R and B gain less than 192 , Adjust is O.K.)
2) If G gain is less than 172, Increase G gain by up to 172,
and then increase R gain and G gain same amount of
increasing G gain.
3) If R gain or B gain is over 255, Readjust G gain less
than 172, Conform to R gain is 255 or B gain is 255
Color Analyzer
Computer
Pattern Generator
RS-232C
RS-232C
RS-232C
Probe
Signal Source
* If TV internal pattern is used, not needed
Adj. item
Command
(lower caseASCII)
Data Range
(Hex.)
Default
(Decimal)
CMD1 CMD2 MIN MAX
Cool
R Gain j g 00 C0 TBD
G Gain j h 00 C0 TBD
B Gain j i 00 C0 TBD
R Cut TBD
G Cut TBD
B Cut TBD
Medium
R Gain j a 00 C0 TBD
G Gain j b 00 C0 TBD
B Gain j c 00 C0 TBD
R Cut TBD
G Cut TBD
B Cut TBD
Warm
R Gain j d 00 C0 TBD
G Gain j e 00 C0 TBD
B Gain j f 00 C0 TBD
R Cut TBD
G Cut TBD
RS-232C
COMMAND
Explanation
CMD DATA ID
Wb 00 00 Begin White Balance adj.
Wb 00 ff End White Balance adj. (internal pattern disappears )