LG 27UL550 User manual
Internal Use Only
P/NO :
CHASSIS :
MODEL :
CAUTION
BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
SERVICE MANUAL
MFL62449373(1906-REV01)
27UL550
27BL55U
LM8CA
LED LCD MONITOR
- 2 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
CONTENTS
CONTENTS ............................................................................................................................................................ - 2 -
SAFETY PRECAUTIONS ............................................................................................................................................ - 3 -
SPECIFICATION....................................................................................................................................................... - 4 -
ADJUSTMENT INSTRUCTION ................................................................................................................................... - 17 -
BLOCK DIAGRAM .................................................................................................................................................. - 26 -
EXPLODED VIEW................................................................................................................................................... - 27 -
ASSEMBLE AND DISASSEMBLE ............................................................................................................................... - 28 -
TROUBLE SHOOTING GUIDE.................................................................................................................................... - 30 -
SAFETY PRECAUTIONS
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 modif
y
the ori
g
inal desi
g
n without
p
ermission of manufacturer.
IMPORTANT SAFETY NOTICE
General Guidance An other abnormality exists that must be corrected before the
An isolation Transformer should always be used during the receiver is returned to the customer.
servicing of a receiver whose chassis is not isolated from the AC
Leakage Current Hot Check (See below Figure)
power line. Use a transformer of adequate power rating as this
Plug the AC cord directly into the AC outlet.protects the technician from accidents resulting in personal injury
from electrical shocks.
Do not use a line Isolation Transformer during this check.
Connect 1.5 K / 10 watt resistor in parallel with a 0.15 uF capacitorIt will also protect the receiver and it's components from being
between a known good earth ground (Water Pipe, Conduit, etc.)damaged by accidental shorts of the circuitry that may be
and the exposed metallic parts.inadvertently introduced during the service operation.
Measure the AC voltage across the resistor using AC voltmeterIf any fuse (or Fusible Resistor) in this TV receiver is blown,
with 1000 ohms/volt or more sensitivity.replace it with the specified.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Any voltageWhen replacing a high wattage resistor (Oxide Metal Film Resistor,
measured must not exceed 0.75 volt RMS which is corresponds toover 1 W), keep the resistor 10 mm away from PCB.
0.5 mA.Keep wires away from high voltage or high temperature parts.
In case any measurement is out of the limits specified, there is
Before returning the receiver to the customer, possibility of shock hazard and the set must be checked and
always perform an AC leakage current check on the exposed repaired before it is returned to the customer.
metallic parts of the cabinet, such as antennas, terminals, etc., to
Leakage Current Hot Check circuit
be sure the set is safe to operate without damage of electrical
shock.
- 3 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
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. When 25A is impressed between Earth and 2nd Ground
If the exposed metallic part has a return path to the chassis, the for 1 second, Resistance must be less than 0.1
*Base on Adjustment standard
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.
- 4 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
SPECIFICATION
1. General Specification
No Item Content Measurement Result Remark
1 Customer BRAND Checked BRAND : LGE
Product
2 User Model Name 27UL550 / 27UL500/27BL55U Checked 1pole stand
3 Sale region Worldwide Checked
4 Feature 27 ”LCD MONITOR (ADS UHD HDR) Checked ADS =BOE IPS
name
5 Chassis Name LM8CA
Checked PCB, Product
spec., Adjustment
spec.
6 General
Scope
External SW
& Adj. Joystick switch Up / Down / Left /
Right / OK Checked Press and Hold :
Power off
Function
Picture Mode, Ratio, S.E.S, Six Color, On
Screen Control,HDR10, Dual Controller,
Factory Calibration
Checked
7 Input
HDMI IN HDMI1(2.0) / HDMI2 (2.0) /HDMI1(1.4) /
HDMI2 (1.4) Checked
DP IN Display Port(1.4) /Display Port(1.2) /Display
Port(1.1) Checked
Display Port(1.4)
Î for HDR
function
USB-C IN N/A N/A Do not provide
USB DN N/A N/A Do not provide
H/P OUT Audio L/R Checked
RS-232C N/A N/A Do not provide
8 Power Cord
Length 1.55±0.05m: 1.55m Refer to Suffix
standard and
power cord Table.
Weight 0.174kg ± 10%, 0.173kg
Color White Checked
9 Cable
Phone to
RS-232
Length 0.2 ± 0.01m N/A
Do not provide
Weight 0.02kg ± 10%, N/A
Color Black N/A
USB C To C
Cable
Length 1.8 ± 0.03m N/A
Do not provide
Weight 0.0775kg ± 5% N/A
Color White N/A
Impedance
1) CABLE : 90 Ω±15Ω
2) CONNECTOR : 90
Ω±10Ω
N/A
DisplayPort Length 1.50m±0.05m 1.5m P/N :
EAD63749403
Weight 0.136kg ± 10% 0.135kg
Color White Checked (Refer to BOM)
Impedance
1) CABLE : 100Ω±5Ω
2) CONNECTOR :
100Ω±10Ω
1)
98.37~101.9ohm
2)
92.33~102.7ohm
HDMI
Length 1.50m ± 0.05m 1.5m
P/N :
EAD63954402
(Refer to BOM)
Weight 0.090kg ± 10% 0.090kg
Color White Checked
Impedance
1) CABLE : 100Ω±5Ω
2) CONNECTOR :
100Ω±10Ω
1)
96.69~105.73ohm
2)
90.73~108.97ohm
10 Power (Adapter /
PSU /LPB)
Output: DC 19V 2.1A, 40W Adapter
Color: White, Weight : 0.166kg ±10%, with
PE bag
Checked
P/N :
EAY62850505
(Refer to BOM)
11 Power Rating Input : DC 19V / 2.0 A Checked Request to
regulation team
12 Accessory Box - - Not applied
13 Applying module list
P/No Specification
Checked
27” UHD
MODULE (BOE)
EAJ65029401 MV270QUM-N30
- 5 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2. Signal Timing (Resolution)
1. Signal (Video & Sync) – Display Port
Mode section polarity DOT CLOCK
[MHz]
Frequency
[kHz]/[Hz]
Total
Period(E)
Display
(A)
Front
Porch(D)
Sync.
(C)
Back
Porch(B) Resolution Remark
1 H(Pixels) - 25.175 31.469 800 640 16 96 48 640 x 480 PC :
Display
Resolution
Information
V(Lines) - 59.94 525 480 10 2 33
2 H(Pixels) + 40 37.879 1056 800 40 128 88 800 x 600
V(Lines) + 60.317 628 600 1 4 23
3 H(Pixels) - 65 48.363 1344 1024 24 136 160 1024 x 768
V(Lines) - 60 806 768 3 6 29
4 H(Pixels) + 79.99 54.347 1472 1152 32 96 192 1152 x 864
V(Lines) + 60.05 905 864 1 3 37
5 H(Pixels) + 74.250 45.00 1650 1280 110 40 220 1280 x 720
V(Lines) + 60.00 750 720 5 5 20
6 H(Pixels) - 83.5 49.702 1680 1280 72 128 200 1280 x 800
V(Lines) + 59.810 831 800 3 6 22
7 H(Pixels) + 108 63.981 1688 1280 48 112 248 1280 x 1024
V(Lines) + 60.02 1066 1024 1 3 38
8 H(Pixels) + 108.00 60.00 1800 1600 24 80 96 1600 x 900
V(Lines) + 60.00 1000 900 1 3 96
9 H(Pixels) + 148.5 67.5 2200 1920 88 44 148 1920 x 1080
V(Lines) - 60 1125 1080 4 5 36
10 H(Pixels) + 277.25 133.32 2080 1920 48 32 160 1920 x 2160
V(Lines) - 60 2222 2160 54 5 3
11 H(Pixels) + 241.50 88.79 2720 2560 48 32 80 2560 x 1440
V(Lines) - 59.95 1481 1440 3 5 33
12 H(Pixels) + 266.64 66.66 4000 3840 8 144 8 3840 x 2160
V(Lines) - 30 2222 2160 54 5 3
13 H(Pixels) + 533 133.32 4000 3840 8 144 8 3840 x 2160
V(Lines) - 60 2222 2160 54 5 3
- 6 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2 Signal (Video & Sync) – HDMI
Mode section polarity DOT
CLOCK[MHz]
Frequency
[kHz]/[Hz]
Total
Period(E)
Display
(A)
Front
Porch(D)
Sync.
(C)
Back
Porch(B) Resolution Remark
1 H(Pixels) - 25.175 31.469 800 640 16 96 48 640 x 480 PC : Display
Resolution Information
V(Lines) - 59.94 525 480 10 2 33
2 H(Pixels) + 40 37.879 1056 800 40 128 88 800 x 600
V(Lines) + 60.317 628 600 1 4 23
3 H(Pixels) - 65 48.363 1344 1024 24 136 160 1024 x 768
V(Lines) - 60 806 768 3 6 29
4 H(Pixels) + 79.99 54.347 1472 1152 32 96 192 1152 x 864
V(Lines) + 60.05 905 864 1 3 37
5 H(Pixels) + 74.250 45.00 1650 1280 110 40 220 1280 x 720
V(Lines) + 60.00 750 720 5 5 20
6 H(Pixels) - 83.5 49.702 1680 1280 72 128 200 1280 x 800
V(Lines) + 59.810 831 800 3 6 22
7 H(Pixels) + 108 63.981 1688 1280 48 112 248 1280 x
1024
V(Lines) + 60.02 1066 1024 1 3 38
8 H(Pixels) + 108.00 60.00 1800 1600 24 80 96 1600 x 900
V(Lines) + 60.00 1000 900 1 3 96
9 H(Pixels) + 148.5 67.5 2200 1920 88 44 148 1920 x
1080
V(Lines) - 60 1125 1080 4 5 36
10 H(Pixels) + 277.25 133.29 2080 1920 48 32 160 1920 x
2160
V(Lines) - 60 2222 2160 54 5 3
11 H(Pixels) + 241.50 88.79 2720 2560 48 32 80 2560 x
1440
V(Lines) - 59.95 1481 1440 3 5 33
12 H(Pixels) + 297 67.5 4400 3840 176 88 296 3840 x
2160
V(Lines) - 30 2250 2160 8 10 72
13 H(Pixels) + 594 135 4400 3840 176 88 296 3840 x
2160
V(Lines) - 60 2250 2160 8 10 72
3 HDMI Video input (Refer to Manual)
Factory support
mode
Horizontal
frequency
Vertical
frequency
(Preset Mode) (KHz) (Hz)
1 480P 31.5 60
2 720P 45 60
3 1080P 67.5 60
4 2160P 135 60
Supporting timing
●Estabilisied I, Estabilisied II, Manufacturer Timing
●Standard Timing
●Detailed Timing (1Page)
- 7 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
EDID 2Page 영역의 Video Short Block Description
수평
크기
수직
크기 주사방식 주파수 비율 HDMI 1.4 HDMI 2.0
HDMI FreeSync
DP
DP FreeSync
640 480 P 59.94/60 4:3 ● ● ●
720 480 P 59.94/60 4:3
720 480 P 59.94/60 16:9 ● ● ●
720 576 P 50 16:9 ● ●
1280 720 P 59.94/60 16:9 ● ● ●
1920 1080 P 23.98/24 16:9 ●
1920 1080 P 29.97/30 16:9 ● ●
1920 1080 P 50 16:9 ● ●
1920 1080 P 59.94/60 16:9 ● ● ●
3840 2160 P 23.98/24 16:9 ●
3840 2160 P 25 16:9 ●
3840 2160 P 29.97/30 16:9 ●
3840 2160 P 50 16:9 ●
3840 2160 P 59.94/60 16:9 ●
zHDMI1.4 : HDMI1/2 : HDMI ULTRA Deep Color : OFF
zHDMI2.0 : HDMI1/2 : HDMI ULTRA Deep Color : ON
- 8 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
- 9 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
EDID 2Page 영역의 Audio Short Block Description
입력 Audio 포맷 CH 지원 주파수(kHz) Bit rate 지원 유무 Remark
HDMI 1.4 / 2.0
HDMI FREE-SYNC
PCM 2 32 / 44.1 / 48 16Bit, 20Bit, 24Bit ●
AC3 6 32 / 44.1 / 48 640kHz(Max.)
DTS 6 44.1 / 48 1536kHz(Max.)
DP
DP FREE-SYNC
PCM 2 32 / 44.1 / 48 16Bit, 20Bit, 24Bit ●
AC3 6 32 / 44.1 / 48 640kHz(Max.)
DTS 6 44.1 / 48 1536kHz(Max.)
EDID 내의 Color Depth Description
입력 Bit 지원유무 Remark
HDMI 1.4 / 2.0
HDMI FREE-SYNC
8
10 ● Extension VSDB 내 6 번째 byte = [B8]
DP
DP FREE-SYNC
8 1page 내 0x14h = [A5]
10 ● 1page 내 0x14h = [B5]
zHDMI1.4 : HDMI1/2 : HDMI ULTRA Deep Color : OFF
zHDMI2.0 : HDMI1/2 : HDMI ULTRA Deep Color : ON
3. LCD Panel Characteristic
No Item Content Remark
1 LCD Module
Feature
Maker BOE
Refer to CAS
Type
A
DS (IPS)
A
ctive Displa
y
Area 27.0 inches
(
68.47cm
)
dia
g
onal
(
Aspect ratio 16:9
)
Pixel Pitch [mm] 0.1554 [mm] X 0.1554 [mm]
Electrical Interface eDP
Color Depth 1.07 Billion colors, 10 Bit (8bit + A-FRC)
Size (Outline) [mm] 611.8(H) x 355.6(V) x 13.5(D)mm (Typ.)
Surface Treatment Haze 25%, (3H)
Operating Mode Normally black
Back light Unit White LED
Color Gamut sRGB 98%
Standard Measurement Condition
zAmbient Luminance Level : dark ( < 10 lux)
zAmbient Temperature : Normal Temperature(10 ~ 25 ℃)
zwarm-up Time : More than 30min (at Full White Pattern)
zInput Signal : 3840X2160@60Hz
zContrast : 70 / Brightness : Max. 100
z6500K : Color Temperature Setting is 6500 K( if it’s not special specification)
zAnother Spec.: Product Specification Standard( LG(55)G1-1034 )
zCosmetic Spec. : LCD Module IIS Spec.
4.EDID
2.1 EDID
No Item Content Measurement Result Remark
1 Manufacturer ID GSM1) Checked Hex : 1E 6D
2 Product ID HDMI1/2 : 30470
DP : 30471 Checked Hex : 77 06
Hex : 77 07
3 Year / Week Year : 19 (2015 year)
Week : 1 (1 week) Checked Inserted at Production Line
(Variable data)
4 Version 1 Checked EDID Version
5 Revision
HDMI : 3
DP : 4
Checked
EDID Revision
6 Serial Number Refer to variable data file Checked Inserted at Production Line
(Variable data)
7 Model Name LG HDR 4K Checked
8 Check Sum Refer to variable data file Checked (Variable data)
- 10 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
9 Color Depth (0x14h) 8bit / 10bit Checked A5 / B5
EDID V1.4 Only (DP)
10 Physical Address Separate Port No. Checked HDMI1 : 10
HDMI2 : 20
- 11 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2.1.1 Data
2.1.1.1 HDMI1 EDID (HDMI1.4) : HDMI ULTRA HD Deep Color : OFF
2.1.1.2 HDMI2 EDID (HDMI1.4) : HDMI ULTRA HD Deep Color : OFF
2.1.1.3 HDMI1 EDID (HDMI2.0) : HDMI ULTRA HD Deep Color : ON
- 12 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2.1.1.4 HDMI2 EDID (HDMI2.0) : HDMI ULTRA HD Deep Color : ON
2.1.1.5 .HDMI1 EDID of FREE-SYNC ON Æ Basic mode
2.1.1.6 .HDMI1 EDID of FREE-SYNC ON Æ Extended mode
- 13 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2.1.1.7 .HDMI2 EDID of FREE-SYNC ON Æ Basic mode
2.1.1.8 .HDMI2 EDID of FREE-SYNC ON Æ Extended mode
- 14 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2.1.1.9 . DP EDID (DP1.4)
2.1.1.10 . DP EDID (DP1.2 / DP1.1)
- 15 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2.1.1.11 . DP EDID of FREE-SYNC ON Æ Basic mode
- 16 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2.1.1.12 . DP EDID of FREE-SYNC ON Æ Extended mode
- 17 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
ADJUSTMENT INSTRUCTION
1.Application
1.1ThisdocumentisappliedtoLM8CAchassis27BL55U/27UL550&27UL500LCDMonitorwhichismanufacturedinMonitorFactoryoris
producedonthebasisofthisdata.
1.2ManufacturingType:SET
2.Designation
2.1Theadjustmentisaccordingtotheorderwhichisdesignatedandwhichmustbefollowed,accordingtotheplanwhichcanbe
changedonlyonagreeing.
2.2.PowerAdjustment:FreeVoltage
2.3.MagneticFieldCondition:Nil.
2.4.InputsignalUnit:ProductSpecificationStandard
2.5.Reserveafteroperation:Above5Minutes(HeatRun)
Temperature:at25℃±5°C/Relativehumidity:65±10%/Inputvoltage:100~240V,50/60Hz
2.6.Adjustmentequipments:ColorAnalyzer(CA‐210orCA‐110),DDCAdjustmentJigequipment,
3.MainPCBcheckprocess(SMT)
*APC‐AfterManual‐Insult,executingAPC
3.1ADCProcess
‐27UL550/27BL55U/27UL500doesn’tneedADCprocessbecauseithasonlydigitalinputlikeDisplayPort,HDMI.
3.2MainPCBFunctiontest
‐Checkdisplay/audioaccordingtointerface
3.3WriteHDCP2.2Key
a.WriteHDCPKeyintoFlashmemorybyusingDDC2ABprotocol&HDCPAdjustmentJigequipment.
HDCP2.2WriteCommand:E9AddressHighAddressLowex)E90000
*Theremustbeinputsignal.NoinputsignalcausestheHDCPKeywritefail.
*HDCP1.4Keyisembeddedonscaler.
4. TotalAssemblylineprocess
4.1EDIDSerialNumberWrite
‐ThismodelDON’TneedtowritefullediddataforupdatetheSerialnumber.
JustwritetheS/Ndatabyusingadjustmentcommand.
Send Serial data Send 24 byte
( EDID SN(4byte) + date (2byte) + Ascii SN(18byte) )
Read C/s of Serial data Read checksum data of 24 byte
4.2VerifyHDCPKey
CheckOSDwithagingonmodeorusingMasterSignalgeneratorwithHDCPOnandconnecttomonitorwithHDMI
IftheHDCPKeyisNG,thecolorofbackgroundwillbeRed,andifOK,itscolorwillbeWhiteasbelowpicture.
4.3SetAutomaticStandbytime
a.SetAutomaticStandbytimebyadjustmentjigequipment:Europe:4H,Others:OFF
Commandset:F70001(forEurope–set4h)
F70000(forothers–set0ff)
b.ChecktheAutomaticStandbytimesettingvaluebyadjustmentjigequipment.
Pleasecheckthevalueof0xA60xEEaddress
Value:0x00‐OFF
0x04‐Set4H
4.4Factorycalibration
a. FactoryCalibration(2.2):Gamma,dE,ColorTemperature(6500k)
‐ReferenceModel:27MU67/27UD68/27UD88/27UD58/27UD88/32UD89/27UK850/27UK650/27UK600
‐Input:HDMI1/2,GrayPatternwithGammacorrectionusingcommandusing“AdjustmentCommand”
‐ThismodelmustbecalibratedGamma2.2
Gammacalibrationandverify
※whendoingAdjustment,Pleasemakecircumstanceasbelow.
- 18 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
4.5Whitebalancecheck
‐.Beforethefactorycalibration,checktheWhitebalanceaccordingtobelowspecification.
HDMI1920x1080(or3840x2160),FullWhite
Toleranc e:‐/+0.015/LuminanceSpec(min):250
Checkcondition:custommode(outgoingcondition)
AgingTime[min]xy
20.3190.339
40.3180.338
80.3180.337
100.3170.336
250.3160.333
400.3150.331
2550.3130.329
*Note:ManualW/Bprocess
1)WheninDCOffCondition
2)Pressleftbutton3‐timesandthenrightbutton1‐times,presspowerbutton
3)PressMenu(right‐sideofOSD)buttonandcanseeServiceMenu.
4.6CheckHDR
‐.Beforethefactorycalibration,checktheWhitebalanceaccordingtobelowspecification.
1)HDRModecheck(HDMI)
‐.Equipment:MSPG‐7800
‐.CheckPoint:HDROSDbutthisOSDdisapperinfewseconds
4.7DPMOperationcheck
■MeasurementCondition:100~240V@50/60Hz
- 19 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
1)SetInputtoDisplayPort,HDMI1,HDMI2
- 20 - Copyright © 2019 LG Electronics Inc. All rights reserved.
Only training and service purposes
2)Turnoffthesourcedevice.
3)CheckDPMoperationrefertothebelowtable.
OperatingConditionSync(H/V)
orVideo
EUT
(MSPG6100)LED(SET)Wattage(W)
Sleepmode(DPM)Off/OffOff Off 0.5W
Offmode‐‐Off0.3WDCSwitchOff
5.Shippingcondition
ÆMakesuretodoFACTORYRESETatthefinalprocess.
No. Item Content& Outgoing
Condition 비고
Accessory Refer to BOM / And General
specification(3page)
Full accessory list is included
in general specification
2
Outgoing
Conditio
n
Quick
Settings
Brightness 90
Contrast 70
Volume 30
Color Temp Custom
Input Input List HDMI1 *Input Save ad last
condition
Aspect Ratio Full wide
Picture
Picture Mode Custom
Picture Adjust
Brightness 90
Contrast 70
Sharpness 50
Super Resolution+ Off
Black Level
Depending on input signal
(RGB: High)
(YUV: Low)
DFC Off
Game Adjust
Response Time Fast
FreeSync Off
Black Stabilizer 50
Color Adjust
Gamma Mode 2
Color Temp Custom
Red 50
Green 50
Blue 50
Six Color (Hue/Saturation) 50
Picture Reset No
General
Language Depend on the sale region
Smart Energy Saving Low
Power LED Off
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