37LT760H (CHASSIS:LD2FF) — LG TV Service Manual (repair manual). Page 9

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1. Application Range
This  spec.  sheet  applies  to  LD2FF  Chassis  applied  LCD TV 
all models manufactured in TV factory.
2. Designation
(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 °C ± 5 °C of temperature and 65 % ± 10 % of relative 
humidity if there is no specific designation. 
(4)  The  input  voltage  of  the  receiver  must  keep AC  100-240 
V~, 50/60 Hz.
(5)  The receiver must be operated for about 5 minutes prior to 
the adjustment when module is in the circumstance of over 
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 
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.
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.
3. MAIN PCBA Adjustments
3.1. ADC Calibration
3.1.1. Overview
ADC  adjustment  is  needed  to  find  the  optimum  black  level 
and gain in Analog-to-Digital device and to compensate RGB 
3.1.2. Equipment & Condition
(1) USB to RS-232C Jig
(2)  MSPG-925  Series  Pattern  Generator  (MSPG-925FA, 
pattern - 65)
- Resolution : 1080P Comp1
1920*1080 RGB
- Pattern : Horizontal 100% Color Bar Pattern
- Pattern level : 0.7 ± 0.1 Vp-p
- Image
3.1.3. Adjustment method
(1) Adjustment method
-  Don’t need to adjust ADC because there is data in OTP 
and adjusted initially.
3.2. MAC address D/L, CI+ D/L
3.2.1. Equipment & Condition
1) Play file: keydownload.exe
3.2.2. Communication Port connection
1) Key Write: Com 1,2,3,4 and 115200 (Baudrate)
2) Barcode: Com 1,2,3,4 and 9600 (Baudrate)
3.2.3. Download process
1) Select the download items.
2) Mode check: Online Only
3) Check the test process
- DETECT -> MAC -> CI+
4) Play: START
5) Check of result: Ready, Test, OK or NG
6) Printer Out (MAC Address Label)
3.2.4. Communication Port connection
Connect: PCBA Jig → RS-232C Port== PC → RS-232C Port
3.2.5. Download
3.2.6. Inspection
- In INSTART menu, check these keys.
Play: Start 
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