LG 34WL550 User manual

P/NO :
CHASSIS :
MODEL :
CAUTION
BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
SERVICE MANUAL
Copyright © 2019 LG Electronics Inc. All rights reserved. Only training and service purposes.
CONFIDENTIAL
P/NO : MFL70211523 (1909-REV00)
LED MONITOR
SERVICE MANUAL
LM83B
34WL550 34WL550-BJ
Any reproduction, duplication, distribution (including by way of email, facsimile or other electronic means),
publication, modification, copying or transmission of this Service Manual is STRICTLY PROHIBITED unless you
have obtained the prior written consent of the LG Electronics entity from which you received this Service Manual.
The material covered by this prohibition includes, without limitation, any text, graphics or logos in this Service
Manual.

- 2 - Copyright © LG Electronics Inc. All rights reserved.
Only training and service purposes.
CONTENTS .............................................................................................. 2
SAFETY PRECAUTIONS ........................................................................ 3
SPECIFICATION....................................................................................... 4
ADJUSTMENT INSTRUCTION ................................................................ 6
BLOCK DIAGRAM ................................................................................... 7
EXPLODED VIEW .................................................................................... 8
DISASSEMBLY ........................................................................................ 9
TROUBLE SHOOTING GUIDE .............................................................. 11
CONTENTS

- 3 - Copyright © LG Electronics Inc. All rights reserved.
Only training and service purposes.
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in the
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 - Copyright © LG Electronics Inc. All rights reserved.
Only training and service purposes.
SPECIFICATION
No
Item
Content
Remark
1
Customer
BRAND
BRAND : LGE Product
OEM/ODM : Buyer Model
2
User Model Name
34WL550
3
Sale region
World Wide
4
Feature
34inch WFHD Monitor
5
Chassis Name
LM83B
6
General
Scope
External SW
&Adj.
Joystick
Power off , Menu, Input, Exit
Function
Picture Mode Ratio, Smart Energy Saving, Six Color, Audio
Volume(Speaker)
7
Power Cord
Length
1.55±0.05M
Refer to Suffix standard and
power cord table
Weight
0.17kg±10%,
Color
Black
8
Cable
DisplayPort
Length
-
N/A
Weight
-
Color
-
Impedance
-
HDMI
Length
1.5±0.05 M
EAD65185201
Weight
0.11kg±10%,
Color
Black
Impedance
1) Cable : 100Ω±10%,
9
Power
(Adapter)
Input: AC100~240V 50~60Hz 1.1A
Output: DC 19V 2.1A,40W Adapter
Color : Black, Weight : 0.439kg±10%
EAY62850015
10
Applying module list
P/N
Specification
EAJ65493201
SEM340F0(BD0-
M04)_EPS

- 5 - Copyright © LG Electronics Inc. All rights reserved.
Only training and service purposes.
2. Signal Timing (Resolution)
2.1. Signal (Video & Sync)
2.2. H/V Timing
mode
section
polar
ity
DOT
CLOCK
[MHz]
Frequency
[kHz]/[Hz]
Total
Period
(E)
Display
(A)
Front
Porch
(D)
Sync.
(C)
Back
Porch
(B)
Resolution
1
H(Pixels)
-
25.175
31.469
800
640
16
96
48
640 x 480
V(Lines)
-
59.94
525
480
10
2
33
2
H(Pixels)
-
31.5
37.5
840
640
16
64
120
640 x 480
V(Lines)
-
75
500
480
1
3
16
3
H(Pixels)
+
40.0
37.879
1056
800
40
128
88
800 x 600
V(Lines)
+
60.317
628
600
1
4
23
4
H(Pixels)
+
49.5
46.875
1056
800
16
80
160
800 x 600
V(Lines)
+
75.0
625
600
1
3
21
5
H(Pixels)
-
65.0
48.363
1344
1024
24
136
160
1024 x 768
V(Lines)
-
60.0
806
768
3
6
29
6
H(Pixels)
+
78.75
60.123
1312
1024
16
96
176
1024 x 768
V(Lines)
+
75.029
800
768
1
3
28
7
H(Pixels)
-
81.62
53.697
1520
1152
64
120
184
1152 x 864
V(Lines)
+
60
895
864
1
3
27
9
H(Pixels)
+
74.25
45
1650
1280
110
40
220
1280x720
V(Lines)
+
60
750
720
5
5
20
10
H(Pixels)
+
108
63.981
1688
1280
48
112
248
1280 x1024
V(Lines)
+
60.02
1066
1024
1
3
38
11
H(Pixels)
+
135
79.976
1688
1280
16
144
248
1280 x 1024
V(Lines)
+
75.025
1066
1024
1
3
38
12
H(Pixels)
+
108.0
60.00
1800
1600
24
80
96
1600 x 900
V(Lines)
+
60.00
1000
900
1
3
96
13
H(Pixels)
-
146.25
65.29
2240
1680
104
176
280
1680 x 1050
V(Lines)
+
59.954
1089
1050
3
6
30
14
H(Pixels)
+
148.50
67.50
2200
1920
88
44
148
1920 x 1080
V(Lines)
-
60
1125
1080
4
5
36
15
H(Pixels)
-
181.25
66.636
2720
2560
48
32
80

2560 x 1080
V(Lines)
+
59.98
1111
1080
3
10
18
16
H(Pixels)
-
228.25
83.915
2720
2560
48
32
80
2560 x 1080
V(Lines)
+
74.99
1119
1080
3
10
26

- 6 - Copyright © LG Electronics Inc. All rights reserved.
Only training and service purposes.
BLOCK DIAGRAM

Copyright 2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes
7- - LGE Internal Use Only
EXPLODED VIEW
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
300 200
540
510
500
330
400
910
900

Copyright 2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes 8LGE Internal Use Only
Disassemble method
Fig.1 Place the monitor’s screen face down on a soft cloth.
Fig.2 Disassemble the Stand body with pulling down the button.
ඟ {Gk

Copyright 2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes 9LGE Internal Use Only
Fig 3 Remove the Screw(4EA) and disassemble the back cover
Fig 4 Disassemble the back cover (Latch Type) .
Fig 5 Remove the Speaker (2EA)、Tape(2EA).

Copyright 2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes 10 LGE Internal Use Only
Disassemble method
Fig.6 Disassemble the FFC cable (2EA), cable(2EA).
Fig.7 Disassemble the Screw (2EA).

Copyright 2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes 11 LGE Internal Use Only
Disassemble method
Fig.7 Disassemble the Metal frame assy .
Fig.8 Disassemble the cabinet .

Copyright 2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes 12 LGE Internal Use Only
Disassemble method
Fig.9 Disassemble the main PCB and joy stick cover .

-13 -
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
TROUBLE SHOOTING GUIDE
1. No Power
Replace X100
N
Check C701
Voltage Level (19V) Check Power connector
OK? Replace Adapter
Y
N Y
Check IC703 Output
Voltage Level (3.3V) Replace IC703 &
Recheck
Y
N
Check X100 Clock
27MHz
Check IC701, 702 Output
Voltage Level (5V) Replace IC701, 702 & Recheck
N
Y
Replace IC107 Flash
Memory
Y
Y
Check IC705 Output
Voltage Level (2.5V, 1.2V) Replace IC705 & Recheck
N

-14 -
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
2. No Screen on
Replace FFCable
N
Module Back Light On?
Check IC601, IC602
Replace LED Driver IC
Y
N
N
Check Panel Power 10V (L700)
Check IC700 Output 10V Replace IC700 &
Recheck
Y
N
Check Panel eDP AUX
P300 (#9, 10, 36, 37) Check IC300, IC303
Repair Main B/D
Y
N
Check FFC Cable for Damage or
Open Conductors
Check LED Driver Output
(P601, P602 -1, 2, 5, 6)
Replace T-Con Board or Module
Y
Check P201 (PIN No.69)
Replace G-SYNC Module
N
Check WLED_ENABLE High?
(IC601,IC602 27pin)
Y
Replace G-SYNC Module
N

-15 -
LGE Internal Use Only
Copyright © LG Electronics. Inc. All rights reserved.
Only for training and service purposes
3. No Video – HDMI
Replace the G-SYNC Module
Check input signal format
Is it supported?
Check JK102 for proper
connection or Damage Replace the Connector
N
Y
Check HDMI Cable for Damage or
Open Connector
Y
Check I2C Signal
(EDID) Replace the IC100
N
Y
Check IC102 AUX Signal
(#J1,H1) Replace the IC102
N
Y
Check IC103 AUX Signal
(#3,4) Replace the IC103
N
Y
Y

LGELECTRONICSINC./MONITORDIVISION
Establish:2017/7/12LM80BADJUSTMENTSPECIFICATION1/11
Revision:0
LG electronics






LM83B
AdjustSpecification





34WK650
29WK600
34BL650
34WL500
29WL500
34WL50S
29WL50S
34WL60TM
34WL600
34WL550


HomeEntertainmentCompany
Monitor/PCBD/MonitorDev.Lab.

LGELECTRONICSINC./MONITORDIVISION
Establish:2017/7/12LM80BADJUSTMENTSPECIFICATION2/11
Revision:0
LG electronics
LGELECTRONICSINC.



RevisionHistory
No.DateRevisedbyCause&ListRemark
017.07.12HyunkyuChoEstablished
117.07.20SunjiaqiAdd panel option
217.07.24XuChanghua
AddHDMICompatibilityModeonshippingconditi
on

317.09.20XuChanghuaAddModuleSelectionaddress
417.09.21ZhoumainingDeleteHDCP1.4write
518.01.08ZhoumainingAdd34BK650information
618.09.10ZhoumainingChangegammaadjustspec(x,y)
718.09.28ZhoumainingAddAPD4HwithRUregion
818.12.24BW.KIMUpdateRTKscalermodel.
918.12.27SoogilLeeUpdate Panel information
1018.12.28XuChanghuaUpdate Panel name
1119.02.27ChenYuUpdatemoduleselectionof34WL500,29WL500P11
1219.02.28ChenYuSeparate29WL500,29WK500modulenameP11
1319.03.20BW.KIMAddWL50Sinformations
1419.05.13MingLeiCombineWL500andWL50S
1519.05.21WangXueqian
AddSkyworthpaneladdress,andaddWBajust
fornewpanel.Changepanelcheckaddress

1619.05.23MingLei
UpdateWhitebalancewarmLuminance
min:260→230
P8
1719.05.24MingLeiAdd34WL50Sskyworthpanelinformation
1819.05.27WangXueqianChangeRGBgainrangeto0‐32
1919.07.15MingLei
Add34WK650*SNskyworth,34WL60TM,34WL600,3
4WL550moduleinformation

2019.08.01MingLeiAdd34BL650skyworthmoduleinformation

LGELECTRONICSINC./MONITORDIVISION
Establish:2017/7/12LM80BADJUSTMENTSPECIFICATION3/11
Revision:0
LG electronics

Note)RefertoECOaboutdetailofrevisionhistory.



LGELECTRONICSINC./MONITORDIVISION
Establish:2017/7/12LM80BADJUSTMENTSPECIFICATION4/11
Revision:0
LG electronics

CONTENTS






1.Application
2.Designation
3.MainPCBcheckprocess
4.TotalAssemblylineprocess
5.Shippingcondition
6.Signalcompositionforadjustment

LGELECTRONICSINC./MONITORDIVISION
Establish:2017/7/12LM80BADJUSTMENTSPECIFICATION5/11
Revision:0
LG electronics
1.Application
1.1ThisdocumentisappliedtoLM83Bchassis34WK650/34BL650/34WL500/29WK600/29WL500/34WL50S/29WL50SLCD
MonitorwhichismanufacturedinMonitorFactoryorisproducedonthebasisofthisdata.
1.2ManufacturingType:SET

2.Designation
2.1Theadjustmentisaccordingtotheorderwhichisdesignatedandwhichmustbefollowed,accordingtotheplanwhichcan
bechangedonlyonagreeing.
2.2.PowerAdjustment:FreeVoltage
2.3.MagneticFieldCondition:Nil.
2.4.InputsignalUnit:ProductSpecificationStandard
2.5.Reserveafteroperation:Above5Minutes(HeatRun)
Temperature:at25℃±5°C/Relativehumidity:65±10%/Inputvoltage:100~240V,50/60Hz
2.6.Adjustmentequipments:ColorAnalyzer(CA‐210orCA‐110),DDCAdjustmentJigequipment,

3.MainPCBcheckprocess(SMT)
*APC‐AfterManual‐Insult,executingAPC

3.1ADCProcess
‐34WK650/29WK600doesn’tneedADCprocessbecauseithasonlydigitalinputlikeDisplayPort,HDMI.

3.2MainPCBFunctiontest
‐Checkdisplay/audioaccordingtointerface

3.3‐1WriteHDCP2.2Key
a.WriteHDCPKeyintoFlashmemorybyusingDDC2ABprotocol&HDCPAdjustmentJigequipment.
HDCP2.2WriteCommand:F9AddressHighAddressLowex)F90000
*Theremustbeinputsignal.NoinputsignalcausestheHDCPKeywritefail.
HDCP2.2 writecommand 확
인