LG 24BK550Y User manual

Internal Use Only
CHASSIS :
MODEL :
CAUTION
BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
SERVICE MANUAL
LED MONITOR
SERVICE MANUAL
LM6JA
24BK550Y
27BK550Y

- 2 -
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
CONTENTS .............................................................................................. 2
SAFETY PRECAUTIONS ........................................................................ 3
SPECIFICATION ....................................................................................... 4
Firmware Upgrade Method ............................................................... 8
TROUBLE SHOOTING GUIDE .............................................................. 19
BLOCK DIAGRAM ................................................................................. 14
EXPLODED VIEW .................................................................................. 15
DISASSEMBLY ...................................................................................... 16
CONTENTS

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LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the
Schematic Diagram and Exploded View.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to prevent
Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.
General Guidance
An isolation Transformer should always be used during the
servicing of a receiver whose chassis is not isolated from the AC
power line. Use a transformer of adequate power rating as this
protects the technician from accidents resulting in personal injury
from electrical shocks.
It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitry that may be
inadvertently introduced during the service operation.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1 W), keep the resistor 10 mm away from PCB.
Keep wires away from high voltage or high temperature parts.
Before returning the receiver to the customer,
always perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as antennas, terminals, etc., to
be sure the set is safe to operate without damage of electrical
shock.
Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source, connect an
electrical jumper across the two AC plug prongs. Place the AC
switch in the on position, connect one lead of ohm-meter to the AC
plug prongs tied together and touch other ohm-meter lead in turn to
each exposed metallic parts such as antenna terminals, phone
jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1 MΩand 5.2 MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
Leakage Current Hot Check (See below Figure)
Plug the AC cord directly into the AC outlet.
Do not use a line Isolation Transformer during this check.
Connect 1.5 K / 10 watt resistor in parallel with a 0.15 uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC voltmeter
with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Any voltage
measured must not exceed 0.75 volt RMS which is corresponds to
0.5 mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
Leakage Current Hot Check circuit
IMPORTANT SAFETY NOTICE
To Instrument's
exposed
METALLIC PARTS
Good Earth Ground
such as WATER PIPE,
CONDUIT etc.
AC Volt-meter
SAFETY PRECAUTIONS

- 4 -
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
SPECIFICATION
NOTE : Specications and others are subject to change without notice for improvement.
1. General Specication
No Item Content Remark
1 Customer BRAND
2 User Model Name 24/27BK550Y
3 Sale region Refer to Suffix standard
4 Feature 24/27” LCD MONITOR
5 Chassis Name LM6JA
6 General
Scope
External SW
&Adj. Tact Key (Menu, Left, Right, Up, Down, OK/Input, Power)
Function
OSD,DDC2B,DDC2AB, HDCP, OSD Lock, Ratio, Smart
Energy Saving, Color Weakness, SUPER
RESOLUTION+, Black Level, Black
Stabilizer, OnScreen Control
7 Input &
Output
HDMI IN - 1ea at the back
DVI IN - 1ea at the back
DP IN DP 1.2 1ea at the back
D_SUB IN - 1ea at the back
AUDIO IN Audio L/R IN 1ea at the back
HP OUT Audio L/R OUT 1ea at the back
Speaker Speaker L/R(1.2W Setting) Bottom
USB 1UP, 2Down
8 Power Cord
Length : 1.8±0.05M
Shape : Wall-out
Color : Black
Length : 1.2±0.05M(DC cable length)
1.0±0.05M(power cord)
Shape : desktop
Color : Black
Refer to Suffix
standard and power
cord table
9 Cable
Signal Cable
(DP)
Length : 1.8m
Shape : Detachable Type
Color : Black
Pin : Triple Row, 20 Pin DP
Refer to Suffix
standard
Signal Cable
(HDMI)
Length : 1.8m
Shape : Detachable Type
Color : Black
Pin : 19Pin HDMI
Refer to Suffix
standard
Signal Cable
(DVI)
Length : 1.8m
Shape : Detachable Type
Color : Black
Pin : 24Pin DVI
Refer to Suffix
standard
Audio
Length : 1.8m
Color:Black ,
Pin:2P
Refer to Suffix
standard
10 Power Input: AC100~240V 50~60Hz,1.5A Max Built-in PSU

- 5-
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
SPECIFICATION
11 Set Power Rating N/A (Built-in PSU)
12 Applying module list
P/N Specification
CAS
EAJ62570001 LM238WF1-SJE1, FHD
[LGE Approval]
CAS L M 238WF1-S
EAJ63948301 MV270FHM-N20, FHD
M V 270FHM -N 20
Product S
p
ecifica
t
13 Speaker P/N: EAB51749310 Typ:1.2W*1.2W -

- 6-
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
2. Signal Timing (Resolution)
2.1. Signal (Video & Sync)
Video
Sync
A
B
C
DEF
6. 2 H/V Timing
MODE CLASSIF
ICATION
Polar
ity
DOT
CLOCK
[MHz]
Frequency
[kHz]/
[Hz]
Tota l
Period
(E)
Display
(A)
Front
Porch
(D)
Sync.
(C)
Back
Porch
(B)
Resolution
1 H(Pixels) - 28.321 31.468 900 720 18 108 54 720 X 400
V(Lines) + 70.08 449 400 12 2 35
2 H(Pixels) - 25.175 31.469 800 640 16 96 48 640 x 480
V(Lines) - 59.94 525 480 10 2 33
3 H(Pixels) - 31.5 37.5 840 640 16 64 120 640 x 480
V(Lines) - 75 500 480 1 3 16
4 H(Pixels) + 40.0 37.879 1056 800 40 128 88 800 x 600
V(Lines) + 60.317 628 600 1 4 23
5 H(Pixels) + 49.5 46.875 1056 800 16 80 160 800 x 600
V(Lines) + 75.0 625 600 1 3 21
6 H(Pixels) - 65.0 48.363 1344 1024 24 136 160 1024 x 768
V(Lines) - 60.0 806 768 3 6 29
7 H(Pixels) + 78.75 60.023 1312 1024 16 96 176 1024 x 768
V(Lines) + 75.029 800 768 1 3 28
8 H(Pixels) + 108.0 67.500 1600 1152 64 128 256 1152 x 864
V(Lines) + 75.000 900 864 1 3 32
9 H(Pixels) + 108.0 63.981 1688 1280 48 112 248 1280 x 1024
V(Lines) + 60.02 1066 1024 1 3 38
10 H(Pixels) + 135.0 79.976 1688 1280 16 144 248 1280 x 1024
V(Lines) + 75.025 1066 1024 1 3 38
11 H(Pixels) - 146.25 65.290 2240 1680 104 176 280 1680 x 1050
V(Lines) + 59.954 1089 1050 3 6 30
12 H(Pixels) + 148.50 67.50 2200 1920 88 44 148 1920 x 1080
V(Lines) + 60 1125 1080 4 5 36
zD-SUB/DVI DTV Mode is not supported (interlace mode)

- 7-
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
2.3. HDMI Video input
Factory support
mode
(Preset Mode)
Horizontal
frequency
(KHz)
Vertical
frequency
(Hz)
HDMI
1 480P 31.5 60 O
2 576P 31.25 50 O
3 720P 37.5 50 O
4 720P 45 60 O
5 1080P 56.25 50 O
6 1080P 67.5 60 O
(Recommend Mode)

How to download monitor Firmware
Copyright © 2012 LG Electronics Inc. All rights reserved.
Only for training and service purposes
▶How to do ISP
Step1. Connect Realtek Jig to the monitor and PC.
Step2. Install like as attached file.
Realtek Driver
Install Guide
Connect to Monitor
Connect to PC

How to download monitor Firmware
Copyright © 2012 LG Electronics Inc. All rights reserved.
Only for training and service purposes
Step3. Run “RTDToll”
Step4. [ISP] Icon Click

How to download monitor Firmware
Copyright © 2012 LG Electronics Inc. All rights reserved.
Only for training and service purposes
Step5. Check “Access method”.
[LG Monitor JIG: FTDIUsb]
LG Monitor JIG(P/N RAD33028001)

How to download monitor Firmware
Copyright © 2012 LG Electronics Inc. All rights reserved.
Only for training and service purposes
Step6. Option Check
Enter [ Communication Option ] menu and then uncheck the [ Check ACK]
Set User data(FE2P) area select option

How to download monitor Firmware
Copyright © 2012 LG Electronics Inc. All rights reserved.
Only for training and service purposes
Step7. Following below step
1 Check the Bank 0 checkbox
2 Click [ … ] button
3 select the SW update file( *.bin or *. hex) and then click [ open ] button.

How to download monitor Firmware
Copyright © 2012 LG Electronics Inc. All rights reserved.
Only for training and service purposes
Step8. ISP
Click Thunder icon button
Îyou see the progress bar and the status window.
after finishing SW update, you see the [success] message on status window.

- 14 -
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
BLOCK DIAGRAM

- 15-
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
EXPLODED VIEW
910
900
830
820
120
810
400
LV1
A3
911
300
330
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts
are identified by in the Schematic Diagram and EXPLODED VIEW.
It is essential that these special safety parts should be replaced with the same components as recommended
in this manual to prevent Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.
IMPORTANT SAFETY NOTICE
200

- 16-
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
DISASSEMBLY
1. Preparation 1.1. Preparation tool
Fig.1 Put the MNT on the clean vinyl
Move the one-click button to disassemble the Cable holder and base assy and body assy in order.
Fig.2 Disassemble the screw , (Remove the 4 Screws.)
Fig 3 Disassemble the Back cover by using jig or hand

- 17-
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
Fig 4 Remove the FFC, Lamp, control wafer
<27BK550> <24BK550>
<27BK550> <24BK550>
Fig 5 Disassemble the Chassis assy

- 18-
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
Fig 6 Disassemble the LCD module
Fig 7 Remove the Control PCB for using knife

TROUBLESHOOTING GUIDE
-19-
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. NO POWER
Replace X100
N
Check JP800
Voltage Level (12V)
Check Power
connector
OK ?
Replace Power
Board
Y
N Y
Check IC801 Output
Voltage Level (1.1V,
3.3V)
Replace IC801 &
Recheck
Y
N
Check X100 Clock
14.318MHz
Check IC700
Output
Voltage Level (5VS)
Replace IC700 &
Recheck
N
Y
Replace IC101
Flash Memory
Y

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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
2. NO SCREEN ON
Replace Cable
N
Module Back Light
On?
Check IC100
Replace Main Scaler IC
Y
N N
Check Panel Power
5V(JP125)
Check IC700 Output
5V
Replace IC700 &
Recheck
Y
N
Check Panel Clock
P101(#10,11,22,23)
Check IC100
Repair Main B/D
Y
N
Check FFC Cable
for Damage or
Open Conductors
Check LED Driver
FB
(P700 1,6)
Replace T-Con
Board or Module
Y