LG 19LN4050 (CHASSIS:LB35A) Service Manual ▷ View online
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8. USB S/W Download
* optional, Service only
(1) Put the USB Stick to the USB socket.
(2) Automatically detecting update file in USB Stick.
- If your downloaded program version in USB Stick is lower
than that of TV set, it didn’t work.
Otherwise USB data is automatically detected.
(3) Show the message “Copying files from memory”.
(4) Updating is starting.
(5) Updating Completed, the TV will restart automatically.
(6) If your TV is turned on, check your updated version and
Tool option. (explain the Tool option, next stage)
* If downloading version is more high than your TV have,
TV can lost all channel data. In this case, you have to
channel recover. if all channel data is cleared, you didn't
have a DTV/ATV test on production line.
* After downloading, have to adjust TOOL OPTION again.
1) Push "IN-START" key in service remote control.
2) Select "Tool Option 1" and push "OK" key.
3) Punch in the number. (Each model has their number.)
9. Optional adjustments
9.1. Manual White balance Adjustment
9.1.1. Adjustment 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
1) After Aging Start, Keep the Power ON status during 5
Minutes.
2) In case of LCD, Back-light on should be checked using
no signal or Full-white pattern.
9.1.2. 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 Remot control
(4) Video Signal Generator MSPG-925F 720p/216-Gray
(Model: 217, Pattern: 78)
9.1.3. Adjustment
(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 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) Adj. is performed in COOL, MEDIUM, WARM 3 modes of
color temperature.
■ If internal pattern is not available, use RF input. In EZ Adj.
menu 6.White Balance, you can select one of 2 Test-pattern:
ON, OFF. Default is inner(ON). By selecting OFF, you can
adjust using RF signal in 216 Gray pattern.
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TROUBLE SHOOTING
1. NO POWER-Main PCBA
Is Adapter
Output VOLTAGE 19.4V
through of JK700?
NO POWER
Is 3.3V at C708?
Check waveform of X501
YES
NO
YES
NO
YES
check open or short at Line.
or change Adapter.
check the Lines of IC701,
If there is any problem at Line,
Change IC701
NO
Check Line short or open between
IC501 and X501,
Change IC501 or change X501
1
2
4
Is 1.8V at C745?
is 1.25V at C742?
3
YES
check the Lines of IC711,IC704
If there is any problem at Line,
Change IC704,IC706.
NO
Insert F/W
is 3.3V at 1pin of P120?
when push power key,
Is 0v at 2pin of P120?
Change control
Or check Line short or open of P120
5
is there any waver at 11pin of P120,
when use remote controller?
6
NO
YES
change IR board
Or check Line short or open of P120
NO
4
X501
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2. No raster (Power LED blue, black screen)
Is 19.4V at JK700?
NO RASTER
(Screen is not displayed)
Insert the F/W back
or REPLACE LCD MODULE
Is 1.8V at L501?
Is 1.25V at L500?
Is 1.25V at 4pin of IC704?
Is 1.8V at 2pin of IC711?
YES
NO
YES
NO
YES
Check Line short or open between
IC711/IC704 and IC501,
If there is any problem at Line,
Change IC711/IC704 or change IC501
NO
check open or short at Line and wafer
between IC704,IC711 and IC600.
If there is any problem at Line,
Change IC704,IC711 or IC501
1
2
is 3V at 1pin of IC601?
YES
It is not over 3V at 1pin of IC601.
Change Q601.
Or check Line short or open between
R603 and 95pin of IC501.
Change IC 501.
4
3
NO
check open or short at Line.
or change Adapter
is 12V at 1pin of P101?
If is not under 1.5V at R722,
change Q721 or check open and short
of Line among Q720 and Q721.
If is under 11V at L110,
Check open and short
Of line between L110 and P101.
6
NO
Put into LVDS cable completely?
LVDS cable have damage?
NO
If LVDS cable isn’t insulted enough,
Insult LVDS cable until locking hook.
If LVDS cable have damage,
Change LVDS cable
5
YES
YES
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3. Abnormal/No screen (All input)-Main PCBA
Put into LVDS cable completely?
LVDS cable have damage?
Abnormal/No screen
(all input)
Check waveform at signal
line of P101 (Clock:9,10
Data: 6,7,12,13,15,16,18,19)
YES
NO
YES
NO
YES
If LVDS cable isn’t insulted enough,
Insult LVDS cable until locking hook.
If LVDS cable have damage,
Change LVDS cable
1
Change module
WAVEFORMS
3
Is 12V at 1pin of P101?
If is not under 1.5V at R722,
change Q721 or check open and short
of Line among Q720 and Q721.
If is under 11V at L110,
Check open and short
Of line between L110 and P101.
2
3
NO
Check open and short
Of line between Q720 and P101.
Or Check LVDS cable have damage.
Another is change IC501.
6,7,12,13,15,16,18,19 Pin of 1201
(Data Line)
9,10Pin of P101
(Clock line)
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