DOWNLOAD LG 42LV355B / 42LV355C (CHASSIS:LA0AC) Service Manual ↓ Size: 14.16 MB | Pages: 47 in PDF or view online for FREE

- 13 -

America due to rating 

• Applied model: LA01U Chassis applied None USA

model(CANADA, MEXICO) 

5.3.2 Method  
(1) Press ADJ key on the Adj. R/C, and then select Country

Group Menu 

(2) Depending on destination, select KR or US, then on the

lower Country option, select US, CA, MX.  Selection is
done using +, - KEY 

• Method: Press Adj. key on the Adj. R/C, then select Tool

option.  

6.1.1. GND & HI-POT auto-check preparation  

(1) Check the POWER CABLE and SIGNAL CABE

insertion condition 

6.1.2. GND & HI-POT auto-check  

(1) Pallet moves in the station. (POWER CORD / AV
CORD is tightly inserted) 
(2) Connect the AV JACK Tester. 
(3) Controller (GWS103-4) on. 
(4) GND Test (Auto)  

- If Test is failed, Buzzer operates. 
- If Test is passed, execute next process (Hi-pot test).

(Remove A/V CORD from A/V JACK BOX)  

(5) HI-POT test (Auto) 

- If Test is failed, Buzzer operates. 
- If Test is passed, GOOD Lamp on and move to next

process automatically. 

• TEST voltage

- GND: 1.5KV/min at 100mA
- SIGNAL: 3KV/min at 100mA

• TEST time: 1 second
• TEST POINT

- GND TEST = POWER CORD GND & SIGNAL CABLE

METAL GND

NEUTRAL

• LEAKAGE CURRENT: At 0.5mArms

Step 1) Turn on the TV. 
Step 2) Press EYE button in adjust remote control. 
Step 3) Stay 6 seconds with Eye Q sensor hidden located on

the front of the set. 

Step 4) Check the “Sensor Data” on the screen and check

whether the value is lower thanafter 6 seconds, the
value does not go below 10, Eye Q sensor is not
working properly. Then, change the sensor. 

Step 5) Remove hand from the Eye Q II sensor and stay for 6

seconds. 

Step 6) Check whether the “Back Light (xxx)” value has risen

on the screen. If after 6 seconds and the value still
does not go high, the eye Q II sensor is not working
properly. Replace the sensor. 

42LV355C -UA

55LV355C - UA

Tool 1

26464

46944

Tool 2

10774

10774

Tool 3

53291

53290

Tool 4

2332

2332

Tool 5

16672

24864

 

<Step1>

<Step2>

<Step3>

<Step4>

<Step5>

- 14 -

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 Low, it

didn’t work.  But your downloaded version is High, USB data
is automatically detecting 

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 controller. 
2. Select "Tool Option 1" and Push “OK” button. 
3. Punch in the number. (Each model has their number.) 

- 15 -

Check stand-by Voltage.

P403 9~12pin : +3.5V_ST

Check Power connector

Main B/D 3.5V Line

Short Check

Check X1002 clock

32 KHz

Replace X1002

Check P403 PWR_ON.

1pin : 3.3V

Replace Micom(IC1002) or Main board

Check Multi Voltage

P403 2pin:24V or 24V ,17pin:12V

Replace Power Board

Check Inverter Control & Error Out 

P403 18 pin : High
P403 24 pin : low

Check Power Board or Module

Check IC402/3/5/7 Output Voltage

IC402 : 2.5V

IC403 : 1.26V

IC405 : 3.3V
IC407 : 1.5V

Replace IC402/ 3 / 5 / 7

Re-download Micom software.

Check Micom Voltage
IC1002 pin 48 : +3.5V

Replace L404

Check LVDS Power Voltage

Q409 : 12V

Replace Q409

Check Mstar LVDS Output

Replace Mstar(IC101) or Main Board

Change Module

Check X201 Clock

24 MHz

Replace X201

Replace Power board.

- 16 -

Check RF Cable & Signal

Check Tuner 3.3V Power

L3703

Replace L3703

Check Tuner 1.2V Power 

IC3703  2 pin : 1.2V

Check IF_P/N Signal

TU3702 17/18 Pin

Replace IC3703 

Check Tuner 5V Power

L3702

Check IC406,IC410

Check Mstar LVDS Output

Replace Mstar(IC101) or Main Board.

Replace IC406,IC410

Bad Tuner. Replace Tuner.

Replace L3702