LG 27UL600 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
LM8CA
27UL600
P/NO : MFL69406853(1810-REV00)

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

SPECIFICATION
NOTE : Specications and others are subject to change without notice for improvement.
1. General Specication
1) 27UL650 / 27BL65U / 27UL600
* * Provided accessory: #8/#9 , it’s different marketing request.
No
Item
Content
Measurement
Result
Remark
1
Customer
BRAND
Checked
BRAND : LGE Product
2
User Model Name
27UL650 / 27BL65U / 27UL600
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 Con
trol,HDR400, 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) for HDR function
USB-C IN
N/A
N/A
USB DN
N/A
N/A
H/P OUT
Audio L/R
Checked
RS-232C
N/A
N/A
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
(Refer to BOM)
Weight
0.136kg ± 10%
0.135kg
Color
White
Checked
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 2.53A, 48W Adapter
Color: White, Weight : 0.246kg ±10%, with PE bag
Checked
P/N : EAY62933008
(Refer to BOM)
11
Power Rating
Input : DC 19V / 2.4A
Checked
Request to regulation team
12
Accessory Box
-
-
Not applied
13
Applying module list
P/No
Specification
Checked
27” UHD MODULE (BOE)
For KR Suffix : EAJ64428302
EAJ64428301
MV270QUM-N20

2. Signal Timing (Resolution)
2.1. Signal (Video & Sync)
Video
Sync
A
B
C
DEF
6.1.1 Signal (Video& Sync) – DisplayPort/USB-C
Mode
section
polarity
DOT
CLOCK
[MHz]
Frequency
[kHz]/[Hz]
Total
Period(E)
Display
(A)
Front
Porch(D)
Sync.
(C)
Back
Porch(B)
Resolution
Measurement
Result
Remark
1
H(Pixels)
-
25.175
31.469
800
640
16
96
48
640 x 480
Checked
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
Checked
V(Lines)
+
60.317
628
600
1
4
23
3
H(Pixels)
-
65
48.363
1344
1024
24
136
160
1024 x 768
Checked
V(Lines)
-
60
806
768
3
6
29
4
H(Pixels)
+
79.99
54.347
1472
1152
32
96
192
1152 x 864
Checked
V(Lines)
+
60.05
905
864
1
3
37
5
H(Pixels)
+
74.250
45.00
1650
1280
110
40
220
1280 x 720
Checked
V(Lines)
+
60.00
750
720
5
5
20
6
H(Pixels)
-
83.5
49.702
1680
1280
72
128
200
1280 x 800
Checked
V(Lines)
+
59.810
831
800
3
6
22
7
H(Pixels)
+
108
63.981
1688
1280
48
112
248
1280 x 1024
Checked
V(Lines)
+
60.02
1066
1024
1
3
38
8
H(Pixels)
+
108.00
60.00
1800
1600
24
80
96
1600 x 900
Checked
V(Lines)
+
60.00
1000
900
1
3
96
9
H(Pixels)
+
148.5
67.5
2200
1920
88
44
148
1920 x 1080
Checked
V(Lines)
-
60
1125
1080
4
5
36
10
H(Pixels)
+
277.25
133.32
2080
1920
48
32
160
1920 x 2160
Not support
V(Lines)
-
60
2222
2160
54
5
3
11
H(Pixels)
+
241.50
88.79
2720
2560
48
32
80
2560 x 1440
Checked
V(Lines)
-
59.95
1481
1440
3
5
33
12
H(Pixels)
+
266.64
66.66
4000
3840
8
144
8
3840 x 2160
Checked
V(Lines)
-
30
2222
2160
54
5
3
13
H(Pixels)
+
533
133.32
4000
3840
8
144
8
3840 x 2160
Checked
V(Lines)
-
60
2222
2160
54
5
3
13) Recommended Timing

6.1.2 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
Measurement
Result
Remark
1
H(Pixels)
-
25.175
31.469
800
640
16
96
48
640 x 480
Checked
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
Checked
V(Lines)
+
60.317
628
600
1
4
23
3
H(Pixels)
-
65
48.363
1344
1024
24
136
160
1024 x 768
Checked
V(Lines)
-
60
806
768
3
6
29
4
H(Pixels)
+
79.99
54.347
1472
1152
32
96
192
1152 x 864
Checked
V(Lines)
+
60.05
905
864
1
3
37
5
H(Pixels)
+
74.250
45.00
1650
1280
110
40
220
1280 x 720
Checked
V(Lines)
+
60.00
750
720
5
5
20
6
H(Pixels)
-
83.5
49.702
1680
1280
72
128
200
1280 x 800
Checked
V(Lines)
+
59.810
831
800
3
6
22
7
H(Pixels)
+
108
63.981
1688
1280
48
112
248
1280 x 1024
Checked
V(Lines)
+
60.02
1066
1024
1
3
38
8
H(Pixels)
+
108.00
60.00
1800
1600
24
80
96
1600 x 900
Checked
V(Lines)
+
60.00
1000
900
1
3
96
9
H(Pixels)
+
148.5
67.5
2200
1920
88
44
148
1920 x 1080
Checked
V(Lines)
-
60
1125
1080
4
5
36
10
H(Pixels)
+
277.25
133.29
2080
1920
48
32
160
1920 x 2160
Not support
V(Lines)
-
60
2222
2160
54
5
3
11
H(Pixels)
+
241.50
88.79
2720
2560
48
32
80
2560 x 1440
Checked
V(Lines)
-
59.95
1481
1440
3
5
33
12
H(Pixels)
+
297
67.5
4400
3840
176
88
296
3840 x 2160
Checked
V(Lines)
-
30
2250
2160
8
10
72
13
H(Pixels)
+
594
135
4400
3840
176
88
296
3840 x 2160
Checked
V(Lines)
-
60
2250
2160
8
10
72
12) Recommended Timing (HDMI1.4) , HDMI ULTRA Deep Color : OFF
13) Recommended Timing (HDMI2.0) , HDMI ULTRA Deep Color : ON

BLOCK DIAGRAM

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
510
500
300
310
200
540
or
330
520
910
400
900
920
930

Assembly & Disassembly
■ Disassembly method
Fig.1 Place the monitor’s screen face down on a soft cloth.
.
Fig.2 Disassemble the Stand Base with disassemble the screw.
Fig 3 disassemble the top cover

Fig 4 Remove the screw(2EA) and disassemble stand body.
Fig 5 Remove the Screw(1EA) and disassemble the back cover

Fig.6 Remove the tape and cable and speaker and control PCB assy
Fig.7 Remove the screw (3ea) and disassemble the rear shiled assy
Fig.8 Remove the screw (9ea) and disassemble the Cabinet

TROUBLESHOOTING GUIDE
1. NO POWER
N
Check Power connector
OK ? Replace Adapter
Y
N Y
Y
N
Replace IC601 &
Recheck
N
Y
Replace IC202 Flash Memory
Y
Check JP400,JP401
Voltage Level (19V)
Check IC601 Output
Voltage Level (+3.3V)
Check IC405,IC403, IC404Output
Voltage Level (5V,1.8V, 1.15V)
Replace IC405,IC403, IC404
&Recheck
Check X200 Clock 12MHz Replace X200

2. NO SCREEN ON
Replace Cable
N
Module Back Light On?
Y
N N
Replace IC402 &
Recheck
Y
N
Replace T-Con Board or Module
Y
Check IC 601
Replace Main Scaler IC
Check Panel Power
10V(JP209)
Check WLED_ENABLE High?
(IC601 Pin #27)
Check e-DP Cable for
Damage or Open
Conductors

3. No Video-HDMI
Check signal format and
resolution
Is it supported?
Check JK100 or JK101 for
proper connection or Damage Replace Connector
Y
N
Check HDMI 5V from Source(PC)
(JK100 and JK101)
(Pin No. 18)
Re Download EDID Data
Y
N
Y
Check HDMI Cable for
Damage or Open Connector
Y
Replace Main Scaler (IC200)

4. No Video-DP
Replace Main Scaler (IC200)
Check signal format and
resolution
Is it supported?
Check JK801 for proper
connection or Damage Replace Connector
Y
N
Check AUX Signal
(R137 or R142)
Y
Y
Check DP Cable for Damage
or Open Connector
Y

4. No USB-C
Replace Main Scaler (IC200)
Check input signal format
Is it supported?
Check JK801 for proper
connection or Damage Replace Connector
Y
N
Check AUX Signal
(R876 or R890)
Y
Y
Y
Check USB-CCable for
Damage or Open Connector
N
ReplaceIC801

5. No Sound(H/P)
Replace Main Scaler
(IC200)
Check the Input source.
Check the sound setting in
PC Setting like a right image.
Y
N
Check JK501 Soldering Do re-soldering
Y
N
Y
Check Cable status for
Damaged or Open
Connector
Y

6. No Sound(Speaker)
Check the Input source.
Check Speaker Cable is
connected
Connect the Cable
correctly
Y
N
Replace Speaker and
Check the status
Replace Main Scaler
(IC200)
N
Y
Check Cable for
Damaged or Open
Connector
Y