DOWNLOAD LG 42LC42 (CHASSIS:LP78A) Service Manual ↓ Size: 5.24 MB | Pages: 41 in PDF or view online for FREE

Model
42LC42 (CHASSIS:LP78A)
Pages
41
Size
5.24 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
42lc42-chassis-lp78a.pdf
Date

LG 42LC42 (CHASSIS:LP78A) Service Manual ▷ View online

- 17 -
6.3. Adjustment of White Balance
(For Manual adjustment)
- Operate the zero-calibration of the CA-110 or CA-210, then
stick sensor to LCD module when you adjust. 
- For manual adjustment, it is also possible by the following
sequence
1) Select RF no signal by pressing “POWER ON” key on
remote control for adjustment then operate heat run
more than 15 minutes. 
(If not executed this step, the condition for W/B will be
differ. The W/B condition is Picture Mode : Standard
(MA : Optimum), Color Temp : Normal. )
2) Changing to the av mode by pushing the input or front av
key.
3) Display the internal pattern of the VCT-Pro IC by
pushing the IN-START.
4) Stick sensor to center of the screen and select each
items (Red/Green/Blue Gain and Offset) using 
D
/
E
(CH+/-) key on R/C.
5) Adjust R Gain / B Gain using 
F
/
G
(VOL+/-) key on R/C.
6) Adjust it until color coordination becomes as below. 
(Initially, R/G/B gain and R/G/B offset values are fixed
as below)
Red Gain : 80 ,   Green Gain : 80 ,    Blue Gain : 80
Red Offset : 80,  Green Offset : 80 ,  Blue Offset : 80
* Target Value [Picture Mode : Standard (ZA, TA),
Optimum(MA),  Color Temp: Normal]
-Normal (9300K)    x ; 0.283±0.003  y ; 0.298±0.003
-Luminance(Y)   AV : upper 150 cd/m
2
(Typ : 350 cd/m
2
≥)
=> Reference Value(Automatically fixed)
- Cool(11000K): x:0.274±0.003, y: 0.286±0.003
- Warm(7200K) : x:0.303±0.003, y: 0.319±0.003
<Pattern for Adjustment of White Balance>
7) When adjustment is completed, Exit adjustment mode
using EXIT key on R/C
6.4 Input the Shipping Option Data
1) Push the ADJ key in a Adjust Remote control.
2) Input the Option Number that was specified in the BOM,
into the Shipping area.
3) The work is finished, Push 
A
Key.
7. Default Value in Adjustment mode
(Default values maybe modified the module condition)
7.1. White Balance
<Default Value on OSD>
9. Sound spec.
Item
Dielectric Voltage (AC <-> FG)
Dielectric Voltage (Without FG)
Value
1.5
3
Unit
kV
kV
Remark
At 100mA for 1sec (Line)
At 100mA for 1min (OQC)
At 100mA for 1sec (Line)
At 100mA for 1min (OQC)
Item
Min
Typ
Max
Unit
Remark
Audio Practical Max Output, L(Mono)/R
6
7
9
W
LCD
- 18 -
TROUBLESHOOTING
1. No power
(1) Symptom
1) It is not discharged minutely from the module.
2) Light does not come into the front LED.
(2) Check process
Plug in a power cord
No
Yes
Is plug in power
cord inserted ? 
Connect a cable.
Plasma(CN1), LCD(SC100)
No
Yes
Is the Line Filter and
PSU connected?
Replace the fuse.
No
Yes
Is the fuse of  PSU
normal? Plasma(F101),
LCD(f100)
Connect the 13-14pin cable.
After all cables connect is removed
to PSU, the AC voltage marking is
authorized on manual.
When ST-by 5V is not operated,
replace PSU.
No
Yes
Is it connected
that PSU and 13-14pin
cable in VSC
board?
- 19 -
2. Protect mode
(PDP Only)
(1) Symptom
1) After once shining, it does not discharge minutely from module. 
2) The relay falls.(The sound is audible “Click”.)
3) It is converted with the color where the front LED is red from green.
(2) Check following
Is the Power Board
normal ?
Replace Power Board.
Is output the normality Low/High
voltage except Stand-by 5V?
Yes
No
No
Is the each
connector normal?
Replace the connector.
Replace the fuse.
Replace Y-Board.
After connecting well each connector,
the normality it operates? 
Yes
No
No
Is the Y-Board
normal?
Is the fuse
(FS2,FS3) on Y-B/D
normal?
Is the output voltage
normal after remove P1
connector of Y-B/D?
Yes
No
FS101,
FS102
No
Replace Z-Board.
Is the Z-Board
normal?
Is the fuse
(FS1,FS2) on Z-B/D
normal?
Is the output voltage
normal after remove P1
connector of Z-B/D?
Yes
No
No
Is the X- Board
normal?
Is the
output voltage
normal after remove P1, 2,
3, 4, 5 connector of
X-B/D?
After remove P1, P2, P3 output voltage
normality: Replace Right X-B/D
After remove P4, P5 output voltage
normality: Replace Left X-B/D
No
Yes
Replace the fuse.
Yes
- 20 -
3. No Raster
(1) Symptom
1) No OSD and image occur at screen. 
2) It maintains the condition where the front LED is green.
(2) Check following
4. In case of becomes unusual display from RF mode.
Check the PDP/LCD Module
Replace the
Power board.
Does
minute discharge
at Module?
Is the inverter
/VaVs on?
Is output the normality
Low/High voltage
except Stand-by 5V?
Yes
No
No
Is the Link cable
normal?
Yes
Is the IC500’s
output normal?
Reconnect the link cable in
P803(Plasma)/ P804(LCD).
No
CN700(PDP/LCD)
Replace the VSC.
No
Yes
Check the power.
Is video
output of the
Tuner normal? (Check
TU400_Pin13)
Is the
input voltage
normal?(Check
Pin3)
Is the I2C communication normal?
(Check Pin9, Pin10)
Yes
No
Yes
Is the LVDS
Cable connected
well?
Yes
Change the IC(IC500)
Cable inserts well.
No
No
Check the Tuner.
No
A
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