LG 32LX770M, Service Manual

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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 °C
- 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)
※
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.
RS-232C COMMAND
Explanation
CMD DATA ID
Wb 00 00 Begin White Balance adj.
Wb 00 ff End White Balance adj.
(internal pattern disappears )
(2) Adjustment Map
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
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
Color Analyzer
Computer
Pattern Generator
RS-232C
RS-232C
RS-232C
Probe
Signal Source
* If TV internal pattern is used, not needed