LG 26LE3300-ZA, Service Manual

- 13 -

LGE Internal Use Only

Copyright © 2010 LG Electronics. Inc. All rights reserved.
Only for training and service purposes

4.5. V-COM Adjust(Only LGD(M+S) Module)

- Why need Vcom adjustment?

A

The Vcom (Common Voltage) is a Reference Voltage of
Liquid Crystal Driving.
-> Liquid Crystal need for Polarity Change with every frame.

- Adjust sequence

· Press the PIP key of th ADJ remote control.(This PIP key is

hot key to enter the VCOM adjuting mode)

(Or After enter Service Mode by pushing “ADJ” key, then
Enter V-Com Adjust mode by pushing “

G

” key at “10. V-

Com”

· As pushing the right or the left key on the remote control,

and find the V-COM value which is no or minimized the
Flicker. (If there is no flicker at default value, Press the exit
key and finish the VCOM adjustment.)

· Push the “OK” key to store value. Then the message “Saing

OK” is pop.

· Press the exit key to finish VCOM adjustment.

(Visual Adjust and control the Voltage level)

4.6. Outgoing condition Configuration

- When pressing IN-STOP key by SVC remocon, Red LED are

blinked alternatively. And then Automatically turn off.

(Must not AC power OFF during blinking)

4.7. Internal pressure

Confirm whether is normal or not when between power
board’s ac block and GND is impacted on 1.5 kV(dc) or 2.2
kV(dc) for one second.

5. Model name & Serial number D/L

• Press “Power on” key of service remocon.

(Baud rate : 115200 bps)

• Connect RS232 Signal Cable to RS-232 Jack.
• Write Serial number by use RS-232.
• Must check the serial number at the Diagnostics of SET UP

menu. (Refer to below).

5.1. Signal TABLE

CMD : A0h
LENGTH : 85~94h (1~16 bytes)
ADH : EEPROM Sub Address high (00~1F)
ADL : EEPROM Sub Address low (00~FF)
Data : Write data
CS : CMD + ADH + ADL + …+ Data_n
Delay : 20ms

5.2. Command Set

* Description

FOS Default write : <7mode data> write
Vtotal, V_Frequency, Sync_Polarity, Htotal, Hstart, Vstart, 0,
Phase
Data write : Model Name and Serial Number write in

EEPROM,.

5.3. Method & notice

A. Serial number D/L is using of scan equipment.
B. Setting of scan equipment operated by Manufacturing

Technology Group.

C. Serial number D/L must be conformed when it is produced

in production line, because serial number D/L is mandatory
by D-book 4.0.

CMD 

LENGTH

ADH 

ADL 

DATA_1

. . . 

Data_n 

CS 

DELAY 

No. Adjust 

mode 

CMD(hex)

LENGTH(hex) 

Description 

1 

EEPROM WRITE 

A0h 

84h+n 

n-bytes Write (n = 1~16) 

Row  Li ne

Column  Line

C

LC

C

ST

Pane l

S

Y

S

T

E

M

Gat

e

 Driv

e

 IC

So urce D r i v e  I C

Circuit Block

Ti m i n g  
Co nt r o ll e r

Po w e r  
Blo ck

V

COM

Ga mma
Re f e r e nce V o ltage

Gamm a R eference
Volta ge

Da ta (R ,G,B ) & C ont ro l s ignal

Con t rol si gnal

Data (R ,G,B ) &
Con t rol si gnal

In
te

r

fa

c

e

TFT

Po w e r  I n p u t

Power Input

Da t a  I n p u t

Da t a  I n p u t

V

COM

Liquid 
Crys tal

V

COM