47LH30 (CHASSIS:LA92A) - LG TV Service Manual (repair manual). Page 14

LG Electronics. Inc. All right reserved. 

C

2009

- 14 -

This spec. sheet applies to LA92A Chassis applied LCD TV all
models manufactured in TV factory

1) Because this is not a hot chassis, it is not necessary to use an

isolation transformer.However, the use of isolation
transformer will help protect test instrument.

2) Adjustment must be done in the correct order.
3) The adjustment must be performed in the circumstance of 25

±50ºC of temperature and 65±10% of relative humidity if there
is no specific designation.

4) The input voltage of the receiver must keep 100~240V,

50/60Hz. 

5) The receiver must be operated for about 5 minutes prior to the

adjustment when module is in the circumstance of over 15°C

- In case of keeping module is in the circumstance of 0°C, it

should be placed in the circumstance of above 15°C for 2 hours.

- In case of keeping module is in the circumstance of below -

20°C, it should be placed in the circumstance of above 15°C
for 3 hours.

*Caution) When still image is displayed for a period of 20
minutes or longer (especially where W/B scale is strong.
Digital pattern 13ch and/or Cross hatch pattern 09ch), there
can some afterimage in the black level area.

1) Main PCB check process

• Adjust 480i Comp1
• Adjust 1024*768 RGB
Above adjustment items can be also performed in Final
Assembly if needed. Both Board-level and Final assembly
adjustment items can be check using In-Star Menu

1)ADJUST CHECK.

2)  Final assembly adjustment

• EDID/DDC download
• White Balance adjustment
• RS-232C functionality check
• Factory Option setting per destination
• Ship-out mode setting (In-Stop)

3) Etc

• Ship-out mode
• Service Option Default
• USB Download(S/W Update, Option, Service only)
• ISP Download(Option)

4.1.1 Overview

ADC adjustment is needed to find the optimum black level and
gain in Analog-to-Digital device and to compensate RGB
deviation. 

4.1.2 Equipment & Condition

1) Jig (RS-232C protocol)
2) MSPG-925 Series Pattern Generator(MSPG-925FA)

- Resolution: 480i Comp1(MSPG-925FA model-209, pattern-65)

1024*768 RGB (MSPG-925FA: model-60 , pattern-65)

- Pattern : Horizontal 100% Color Bar Pattern
- Pattern level : 0.7±0.1 Vp-p

4.1.3 Adjustment

4.1.3.1 Adjustment method
• Using RS-232, adjust items listed in 3.1 in the other shown

in “4.1.3.3”

4.1.3.2 Adj. protocol 

Ref.) ADC Adj. RS232C Protocol_Ver1.0

4.1.3.3 Adj. order

• ad 00 00 [Enter ADC adj. mode]
• xb 00 40 [Change input source to Component1(480i)]
• ad 00 10 [Adjust 480i Comp1]
• xb 00 60 [Change input source to RGB(1024*768)]
• ad 00 10 [Adjust 1024*768 RGB]
• ad 00 90 End adj.

Ref) ADC adj. RS232C Protocol_Ver1.0

Protocol     Command 

Set ACK

Enter mode

aa 00 00  d 00 OK00x

Source 

xb 00 40

b 00 OK40x (Adjust 480i Comp1 )

change 

xb 00 60b  00 OK60x (Adjust 1024*768 RGB)

Begin adj. 

ad 00 10

Return 

OKx (Case of Success)

adj. result

NGx (Case of Fail)

Read

(main) (main 

)

adj. data

ad0020 

0000000000000000000000007c007b006dx

(sub ) 

(Sub)

ad 00 21   000000070000000000000000007c00830077x

Confirm adj.  ad 00 99  NG 03 00x (Fail)

NG 03 01x (Fail)

NG 03 02x (Fail)

OK 03 03x (Success)

End adj. 

ad 00 90  d 00 OK90x