LG LRM-519 User manual

SERVICE MANUAL
LG LRM-519 DIGITAL
MEDIA RECORDER
SERVICE MANUAL
MODEL : LRM-519(RV7922M)
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
MODEL : LRM-519(RV7922M)SERVICE MANUAL
P/NO : 3829RVN004L AUGUST, 2005

1-1
SECTION 1
SUMMARY
CONTENTS
PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS............1-2
SERVICING PRECAUTIONS....................................................................................1-3
INTRODUCTION ......................................................................................................1-4
SPECIFICATIONS.....................................................................................................1-5
SYSTEM S/W UPGRADE.........................................................................................1-7
TEST S/W .................................................................................................................1-8

1-2
IMPORTANT SAFETY NOTICE
This manual was prepared for use only by properly trained audio-video service
technicians.
When servicing this product, under no circumstances should the original
design be modified or altered without permission from Zenith Electronics
Corporation. All components should be replaced only with types identical to
those in the original circuit and their physical location, wiring and lead dress
must conform to original layout upon completion of repairs.
Special components are also used to prevent x-radiation, shock and fire haz-
ard. These components are indicated by the letter “x” included in their compo-
nent designators and are required to maintain safe performance. No deviations
are allowed without prior approval by Zenith Electronics Corporation.
Circuit diagrams may occasionally differ from the actual circuit used. This way,
implementation of the latest safety and performance improvement changes
into the set is not delayed until the new service literature is printed.
CAUTION: Do not attempt to modify this product in any way. Never perform
customized installations without manufacturer’s approval. Unauthorized modi-
fications will not only void the warranty, but may lead to property damage or
user injury.
Service work should be performed only after you are thoroughly familiar with
these safety checks and servicing guidelines.
GRAPHIC SYMBOLS
The exclamation point within an equilateral triangle is intended to
alert the service personnel to important safety information in the
service literature.
The lightning flash with arrowhead symbol within an equilateral tri-
angle is intended to alert the service personnel to the presence of
noninsulated “dangerous voltage”that may be of sufficient magni-
tude to constitute a risk of electric shock.
The pictorial representation of a fuse and its rating within an equi-
lateral triangle is intended to convey to the service personnel the
following fuse replacement caution notice:
CAUTION: FOR CONTINUED PROTECTION AGAINST RISK
OF FIRE, REPLACE ALL FUSES WITH THE SAME TYPE AND
RATING AS MARKED NEAR EACH FUSE.
SERVICE INFORMATION
While servicing, use an isolation transformer for protection fromAC line shock.
After the original service problem has been corrected, make a check of the fol-
lowing:
FIRE AND SHOCK HAZARD
1. Be sure that all components are positioned to avoid a possibility of adjacent
component shorts. This is especially important on items trans-ported to and
from the repair shop.
2. Verify that all protective devices such as insulators, barriers, covers, shields,
strain reliefs, power supply cords, and other hardware have been reinstalled
per the original design. Be sure that the safety purpose of the polarized line
plug has not been defeated.
3. Soldering must be inspected to discover possible cold solder joints, solder
splashes, or sharp solder points. Be certain to remove all loose foreign par-
ticles.
4. Check for physical evidence of damage or deterioration to parts and compo-
nents, for frayed leads or damaged insulation (including the AC cord), and
replace if necessary.
5. No lead or component should touch a high current device or a resistor rated
at 1 watt or more. Lead tension around protruding metal surfaces must be
avoided.
6. After reassembly of the set, always perform an AC leakage test on all
exposed metallic parts of the cabinet (the channel selector knobs, antenna
terminals, handle and screws) to be sure that set is safe to operate without
danger of electrical shock. DO NOT USE A LINE ISOLATION TRANS-
FORMER DURING THIS TEST. Use anAC voltmeter having 5000 ohms per
volt or more sensitivity in the following manner: Connect a 1500 ohm, 10
watt resistor, paralleled by a .15 mfd 150V AC type capacitor between a
known good earth ground water pipe, conduit, etc.) and the exposed metal-
lic parts, one at a time. Measure the AC voltage across the combination of
1500 ohm resistor and .15 mfd capacitor. Reverse the AC plug by using a
non-polarized adaptor and repeat AC voltage measurements for each
exposed metallic part. Voltage measured must not exceed 0.75 volts RMS.
This corresponds to 0.5 milliamp AC. Any value exceeding this limit consti-
tutes a potential shock hazard and must be corrected immediately.
TIPS ON PROPER INSTALLATION
1. Never install any receiver in a closed-in recess, cubbyhole, or closely fitting
shelf space over, or close to, a heat duct, or in the path of heated air flow.
2. Avoid conditions of high humidity such as: outdoor patio installations where
dew is a factor, near steam radiators where steam leakage is a factor, etc.
3. Avoid placement where draperies may obstruct venting. The customer
should also avoid the use of decorative scarves or other coverings that
might obstruct ventilation.
4. Wall- and shelf-mounted installations using a commercial mounting kit must
follow the factory-approved mounting instructions. A product mounted to a
shelf or platform must retain its original feet (or the equivalent thickness in
spacers) to provide adequate air flow across the bottom. Bolts or screws
used for fasteners must not touch any parts or wiring. Perform leakage tests
on customized installations.
5. Caution customers against mounting a product on a sloping shelf or in a tilt-
ed position, unless the receiver is properly secured.
6. A product on a roll-about cart should be stable in its mounting to the cart.
Caution the customer on the hazards of trying to roll a cart with small cast-
ers across thresholds or deep pile carpets.
7. Caution customers against using extension cords. Explain that a forest of
extensions, sprouting from a single outlet, can lead to disastrous conse-
quences to home and family.
A.C. Voltmeter
1500 OHM
10 WATT
Place this probe
on each exposed
metal part.
Good Earth Ground
such as the Water
Pipe, Conduit, etc.
0.15uF
PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS

1-3
SERVICING PRECAUTIONS
CAUTION: Before servicing the HD/SD PERSONAL VIDEO
RECORDER & RECEIVER WITH GEMSTAR covered by
this service data and its supplements and addends, read and
follow the SAFETY PRECAUTIONS. NOTE: if unforeseen
circumstances create conflict between the following servic-
ing precautions and any of the safety precautions in this pub-
lications, always follow the safety precautions.
Remember Safety First:
General Servicing Precautions
1. Always unplug the HD/SD PERSONAL VIDEO
RECORDER & RECEIVER WITH GEMSTAR AC power
cord from the AC power source before:
(1)Removing or reinstalling any component, circuit board,
module, or any other assembly.
(2)Disconnecting or reconnecting any internal electrical
plug or other electrical connection.
(3)Connecting a test substitute in parallel with an elec-
trolytic capacitor.
Caution: A wrong part substitution or incorrect
polarity installation of electrolytic capacitors may result
in an explosion hazard.
2. Do not spray chemicals on or near this HD/SD PERSON-
AL VIDEO RECORDER & RECEIVER WITH GEMSTAR
or any of its assemblies.
3. Unless specified otherwise in this service data, clean
electrical contacts by applying an appropriate contact
cleaning solution to the contacts with a pipe cleaner,
cotton-tipped swab, or comparable soft applicator.
Unless specified otherwise in this service data, lubrication
of contacts is not required.
4. Do not defeat any plug/socket B+ voltage interlocks with
which instruments covered by this service manual might
be equipped.
5. Do not applyAC power to this HD/SD PERSONAL VIDEO
RECORDER & RECEIVER WITH GEMSTAR and / or any
of its electrical assemblies unless all solid-state device
heat sinks are correctly installed.
6. Always connect the test instrument ground lead to an
appropriate ground before connecting the test instrument
positive lead. Always remove the test instrument ground
lead last.
Insulation Checking Procedure
Disconnect the attachment plug from the AC outlet and turn
the power on. Connect an insulation resistance meter (500V)
to the blades of the attachment plug. The insulation resis-
tance between each blade of the attachment plug and acces-
sible conductive parts (Note 1) should be more than 1M-
ohm.
Note 1: Accessible Conductive Parts include Metal panels,
Input terminals, Earphone jacks,etc.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged
easily by static electricity. Such components commonly are
called Electrostatically Sensitive (ES) Devices. Examples of
typical ES devices are integrated circuits and some field
effect transistors and semiconductor chip components.
The following techniques should be used to help reduce the
incidence of component damage caused by static electricity.
1. Immediately before handling any semiconductor compo-
nent or semiconductor-equipped assembly, drain off any
electrostatic charge on your body by touching a known
earth ground. Alternatively, obtain and wear a commer-
cially available discharging wrist strap device, which
should be removed for potential shock reasons prior to
applying power to the unit under test.
2. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such
as aluminum foil, to prevent electrostatic charge buildup or
exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder
ES devices.
4. Use only an anti-static solder removal device. Some
solder removal devices not classified as “anti-static”can
generate electrical charges sufficient to damage ES
devices.
5. Do not use freon-propelled chemicals. These can
generate an electrical charge sufficient to damage ES
devices.
6. Do not remove a replacement ES device from its protec-
tive package until immediately before you are ready to
install it. (Most replacement ES devices are packaged with
leads electrically shorted together by conductive foam,
aluminum foil,or comparable conductive material).
7. Immediately before removing the protective material from
the leads of a replacement ES device, touch the protective
material to the chassis or circuit assembly into which the
device will be installed.
Caution: Be sure no power is applied to the chassis or
circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged
replacement ES devices. (Normally harmless motion such
as the brushing together of your clothes fabric or the lifting
of your foot from a carpeted floor can generate static elec-
tricity sufficient to damage an ES device.)

1-4
INTRODUCTION
- MSDVR & DVD Recorder receives the analog NTSC or cable broadcasting and compresses the audio and
video file into the MPEG format to save on HDD or record on DVD.
It supports the additional service of EPG (Electronics Program Guide) provided from MS.
- Configuration
For the CPU, Intel Celeron 733 of x86 is used and for peripheral chips, CPU I/F, Memory I/F and North
Bridge and system parts for the North Bridge part that supports PCI I/F, IDE I/F serial I/F and USB I/F for
graphics function are used.
The Audio/Video signal received from the tuner or external input is compressed through the MPEG Encoder
and saved on HDD to be decoded by the CPU for display and if needed, saved on DVD.
Download or upgrade the MS EPG software through Ethernet and MODEM.
The file can be shared with Windows XP PC through Ethernet or USB I/F WiFi device.
It can be connected to an external HDD, Memory Card Reader, Memory Stick or WiFi device through USB
I/F.
•System Part
- CPU : Celeron 733(Low Voltage)
- North Bridge : 830
- System Memory : SDRAM 128MByte
•MPEG-2 Encoder Part
- MPEG-2 Encoder : CX23418
- PCI I/F ,Video Decoder/ Audio Processor
•Interface Part
- South Bridge : ICH4
- IDE I/F: HDD, DVD±RW
- Super I/O
- Ethernet
- MODEM
- USB 2.0
•Audio/Video In/Out Part
- Tuner
- Video Out
- Audio CODEC

1-5
SPECIFICATIONS
Television System NTSC, Analog American Standard (480i)
Channel Coverage Unscrambled Air/Analog CATV 1-135
Draft Specification
NTSC Reception 1. Terrestrial (ANT/Analog)
2. Cable (CABLE/Analog)
DVD±R/W
USB 2.0
Network 1. Ethernet(10/100)
2. Modem(56kbps)
HDD(160GB)
DVD ± R/W Specifications
DVD DVD-ROM : 4.7GB (Single Layer)
8.5GB (Dual Layer)
DVD-R : 4.7GB (Ver. 2.0 for Authoring : R & W)
4.7GB (Ver. 2.0 for General: read & write )
DVD-RW : 4.7GB (Ver. 1.1 read & write)
DVD+R : 4.7GB/side (Ver. 1.1 read & write)
DVD+RW : 4.7GB/side (Ver. 2.1 read & write)
CD CD-ROM Mode-1 data disc
CD-ROM Mode-2 data disc
CD-ROM XA, CD-I, Photo-CD Multi-Session, Video CD
CD-Audio Disc
Mixed mode CD-ROM disc (data and audio)
CD-Extra, CD-Text
CD-R (Conforming to “Orange Book Part 2”: read)
CD-RW (Conforming to “Orange Book Part 3”: read)
Inputs/Output
RF Input Air/Cable TV (1)
RF Output Out To TV (1) (Loop Out)
Component Video Output Component Out (1), RCA Jack connector 480p,480i -> YPbPr
S-Video Output simultaneous Out with CVBS
S-Video Out (1), 4-pin Mini-DIN
Composite Video Output Video Out, RCA Jack connector (1-Port)
Simultaneous Out with S-video
Video Output Selection Switch 480i -> Composite
480i,480p -> Component Selection
Video In 480i Composite NTSC
Video In with L/R in(2), RCA Jack connector
S-Video In S-Video In, 4-pin Mini-DIN
Audio out L/R Out(2),SPDIF Out(1: Optical, 1: Coaxial)
USB USB2.0(2-Port)
Ethernet 10BASE-T/100BASE-T, RJ45(1)
Modem 56kbps Data Modem, RJ11(1)
VCR/Cable Box Control IR Expender(1), Phone Jack Serial(1)
Chassis Size 430mm(W) x 300mm(D) x 59mm(H)

1-6
* DVR –Recording & Scheduling
•Instant recording / Series recording / Manual recording
•Conflict management
•Duplicate checking (recognize and ignore reruns and repeats)
* DVR - Live TV
•90 minutes buffer
•Recording Pause buffer
•Buffers live TV while playing a recorded TV program
* DVR - Playback
•Skip ahead : 30 seconds
•Instant Replay : 7 seconds
•Multi speed FF & RW : 3 speed (3x,40x,250x)
•Slow motion : FWD 1/2x
•Frame advance
* DVR –etc.
•DVR functionality can work while DVD burning in progress
•Arrange recorded shows into folders
* Program Guide & Search
•Guide data : 14 days premium service
•Guide date source : dialup or broadband
•Combines channel guides from multiple sources
•Channel filtering
•Search by Title, Category, Topic (keyword)
* DVD - Recording
•Disc Compatibility
DVD-R/DVD-RW, DVD+R/DVD+RW, Double layer
Not support VR mode recording
•DVD burning speed : x4
•Copy programs to DVD
•Create the DVD top menu and program info submenu
•Auto chapter marking : every 10 minutes
•Record shows to DVR while burning a DVD
•Use the box’s other functions during burning process
* DVD - Playback
•Disc Compatibility
DVD-Video, DVD-R/DVD-RW, DVD+R/DVD+RW
DVD-/+RW
Audio CD, CD-R, CD-RW
•Play a DVD or CD
•Angle/Subtitle selection, change audio language
•DVD playback while recording/buffering
* Photo & Music
•Digital photo slideshow
•Play music
•Photo slideshows while playing music
* Networking
•Fetch guide data over broadband
•802.11 a/g wireless USB adaptor support
Vender and model name ?
* Other Features
•Video On Demand(V1.1)
•Software update
•USB memory card reader support

1-7
SYSTEM S/W UPGRADE
1. ON-LINE S/W UPGRADE METHOD
- The software can be upgraded by connecting with Ethernet or MODEM.
Main Menu -> settings -> guide set-up -> ???
The softwares that can be upgraded online are as follows.
- Main S/W
- Bootloader
- DVD Firmware
2. SYSTEM INFORMATION
In this menu, you can check the version, Box ID and basic system information of all the softwares used in the
system.
You can check this information in Main menu-> Settings -> System Information.
The information that can be checked is as follows.
- Main S/W version
- Bootloader version
- DVD Firmware version
The information that can be checked.
- Service ID
- Network Information
- Uptime: Power up time
- BR: Bit rate indication
- CPU temperature

1. TEST METHOD USING THE DEBUG BOARD
There are two test methods when there is an issue with the main board.
When it is not properly booted and the composite video is not displayed, you can check the status of the board
using the Debug Board for debugging prepared in the Debug port of the main board.
The Debug Board is composed as follows.
- 7-Segment that indicates the board status
- The connector interfacing the Debug port
- Boot ROM for testing: Not used.
How to use the Debug Board
The Debug Board is connected to the J802 of the main board.
Error code indicated on the Debug Board
1-8
TEST S/W
Eth
G-
MO
K4 K4K4 K4
ern
RT
L81
Si
CX2
2
8
AFS4
54
Au
Au
Co PAu
Au
Vi Au Vi S
S
830
Cele
S6 S6S6 S6
J802

1-9
During L2 cache initialization, the processor is running at a faster or
slower bus frequency than it is designed for. This is a fatal error, and
the processor will be halted. Detected during cache initialization.
No memory was detected during the memory initialization. This is a
fatal error, and the processor will be halted.
Unsupported memory was detected during the memory initialization.
This is a fatal error, and the processor will be halted.
An invalid timing configuration was detected (e.g. 66 MHz SDRAM
with a 100 MHz host bus frequency).
Both registered and unregistered DIMMs were detected.
An unsupported memory configuration was detected.
The stack was located above 1 Mbyte when attempting to switch to
real mode by a call to the sflDone16 API.
The detected amount of memory does not match the SPD data.
Unsupported The host bus frequency is not supported.
The requested integrity mode is not supported by the Hardware.
Board initialization(SIO, GPIO(A/V Mute) etc.)
Prepare to handle interrupts
initialize caching and shadow ROM to RAM
Super I/O initialization
Initialize local keyboard if present
initialize ATA
chipset pci resource allocation
board specific resource allocation hook
enable memory and i/o address decoding for pci devices
Standard legacy services setup
initialize memory map
Setup the graphics mode for 830M
System Bus Frequency
Mismatch
No Memory Detected
Unsupported Memory Type
Unsupported Timing
Mixed Registered/ Unregistered
DIMMs
Unsupported Memory
Configuration
Invalid Real Mode Stack
SPD and Memory Mismatch
Host Bus Frequency
Integrity Mode Unsupported
board init
interrupt init
Cache init
SIO init
keyboard init
ATA init
csPciAlloc
boardResourceAlloc
pciEnableDecode
lgcyInitSvcs
mmapinit
board video init
0x30
0x31
0x32
0x33
0x34
0x35
0x36
0x37
0x38
0x3A
0x20
0x21
0x22
0x23
0x25
0x26
0x27
0x28
0x29
0x2A
0x22
0x2F
BOOTLOADER ERROR/STATUS CODE
Code Name Interpretation/Description

1-10
2. BOARD TEST METHOD USING THE JIG SET
Diagram of JIG test composition
For the JIG set, use the RV7922M set excluding the main board and HDD.
When using the set for JIG, you must use the Debug Board. You must use the HDD for JIG.
Because of the software protection policy of MS, the service man cannot include the self diagnosis software
for troubleshooting on the mass produced HDD. Therefore Boot ROM and HDD are separately needed to
repair the board.
The MS software policy is configured to only allow the Signed Image to be operated on the Signed Boot ROM.
Main Board
D
VD Loader
HDD
Power

2-1
SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
EXPLODED VIEWS.....................................................................................................................2-2
1. Cabinet and Main Frame Section...........................................................................................2-2
2. Deck Mechanism Section(RL-05)...........................................................................................2-3

2-2
EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION
280
283
A50
A43
A60
A47
A44
A26
A26A
A46
462
250
462
204
474
473
473
474
266
267
261
260
264 263
457
457
471
471
465
472
472
469
261
201
202 203
205
452
463
463
463
463
A
4
3
2
1
BCD

2-3
2. DECK MECHANISM SECTION(RL-05)
1001
A001
A000
A60
1434 1434 1025
1025
1030
1437
1432
1038 1029
1432
1021 1432
1432
1032
1033
1011 1019
1020
1019
1009
1012
1013
1435
1014
1016
1015
1017
1018 1018A
1018B
1018C
1018E 1018D
1006
1436
10241433
1029
1027
1027
1005
1026
1003 1002
A004
A002
1041
1042
1434
1434

3-1
SECTION 3
ELECTRICAL
CONTENTS
ELECTRICAL TROUBLESHOOTING GUIDE ..................................................................................................3-2
1. POWER(SMPS) CIRCUIT ........................................................................................................................3-2
2. SYSTEM PART CIRCUIT .........................................................................................................................3-3
3. VIDEO PART-1..........................................................................................................................................3-5
4. YPBPR VIDEO OUTPUT TROUBLESHOOTING.....................................................................................3-6
5. S-VIDEO VIDEO OUTPUT TROUBLESHOOTING..................................................................................3-7
6. CVBS VIDEO OUTPUT TROUBLESHOOTING.......................................................................................3-8
7. AUDIO TROUBLESHOOTING..................................................................................................................3-9
8. TUNER TROUBLESHOOTING...............................................................................................................3-10
9. ETHERNET TROUBLESHOOTING........................................................................................................3-11
10. MODEM TROUBLESHOOTING...........................................................................................................3-12
11. DVD TROUBLESHOOTING..................................................................................................................3-13
12. IR BLASTER TROUBLESHOOTING....................................................................................................3-14
13. SERIAL (RS-232) TROUBLESHOOTING.............................................................................................3-15
WAVEFORMS..................................................................................................................................................3-16
1. SYSTEM PART-1....................................................................................................................................3-16
2. SYSTEM PART-2....................................................................................................................................3-17
3. VIDEO PART-1........................................................................................................................................3-18
4. VIDEO PART-2........................................................................................................................................3-19
5. VIDEO PART-3........................................................................................................................................3-20
6. VIDEO PART-4........................................................................................................................................3-21
7. AUDIO PART-1........................................................................................................................................3-22
8. AUDIO PART-2........................................................................................................................................3-23
9. AUDIO PART-3........................................................................................................................................3-24
10. ETHERNET PART ................................................................................................................................3-25
11. SUPER IO & FRONT INTERFACE PART.............................................................................................3-26
BLOCK DIAGRAMS........................................................................................................................................3-27
1. TOTAL BLOCK DIAGRAM......................................................................................................................3-27
2. WRING BLOCK DIAGRAM.....................................................................................................................3-28
3. POWER BLOCK DIAGRAM ...................................................................................................................3-29
4. SIGNAL PATH BLOCK DIAGRAM..........................................................................................................3-30
5. BLOCK DIAGRAM..................................................................................................................................3-31
CIRCUIT DIAGRAMS......................................................................................................................................3-32
1. POWER(SMPS) CIRCUIT DIAGRAM ....................................................................................................3-32
2. POWER CIRCUIT DIAGRAM.................................................................................................................3-34
3. CPU CIRCUIT DIAGRAM.......................................................................................................................3-36
4. GMCH CIRCUIT DIAGRAM....................................................................................................................3-38
5. ICH4 CIRCUIT DIAGRAM ......................................................................................................................3-41
6. CLOCK & LPC CIRCUIT DIAGRAM.......................................................................................................3-42
7. MEMORY/IDE CIRCUIT DIAGRAM........................................................................................................3-44
8. LAN/USB/MODEM CIRCUIT DIAGRAM ................................................................................................3-46
9. VIDEO CONVERTER & AC97 CODEC CIRCUIT DIAGRAM ................................................................3-48
10. MPEG-II ENCODER & AV DECODER (CX23418) CIRCUIT DIAGRAM.............................................3-50
11. TUNER & EXTERNAL AV INPUT CIRCUIT DIAGRAM........................................................................3-52
12. AUDIO/VIDEO INPUT INTERFACE CIRCUIT DIAGRAM....................................................................3-54
13. MISCELLANEDUS CIRCUIT DIAGRAM..............................................................................................3-56
14. EXTERNAL I/F CIRCUIT DIAGRAM ....................................................................................................3-58
PRINTED CIRCUIT DIAGRAMS.....................................................................................................................3-60
1. MAIN PRINTED CIRCUIT DIAGRAMS(TOP VIEW) ..............................................................................3-60
2. MAIN PRINTED CIRCUIT DIAGRAMS(BOTTOM VIEW) ......................................................................3-62
3. KEY PRINTED CIRCUIT DIAGRAM.......................................................................................................3-64
4. TIMER PRINTED CIRCUIT DIAGRAM...................................................................................................3-64
5. POWER PRINTED CIRCUIT DIAGRAM................................................................................................3-66

3-2
ELECTRICAL TROUBLESHOOTING GUIDE
NO Proper display port
select
Video Input Cable
connection OK
1. POWER(SMPS) CIRCUIT
Power cable
connection
Front Signal Cable
Connection OK
“HELLO”display
on VFD OK
“LG logo”display
on Monitor OK
NO Front signal cable
connect
NO
NO
NO
NO
NO
Front Power Cable
Connection OK NO Front power cable
connect
Display Cable
Connection OK NO Display Cable
Connect
Display Port
Selection (S800) OK
HDD Image
upgrade
Audio Cable
Connection OK NO Audio Cable
Connect
YES
YES
YES
YES
YES
YESYES
YES
YES
YES
“CH No. & DATE”
display on VFD OK
Audio OK
Video OK
Normal TV
Function OK

3-3
2. SYSTEM PART CIRCUIT
Power Cable
Connection Power on
LED801 “ON”OK
“LG logo”display
on Monitor OK
system function
OK
NO Check soldering
state of Board
NO
C919 +1.25V OK
IC900 change
NO IC900 (1-Pin) +12V
OK
NO
NO
Q909 (2-Pin)
Low=0V OK
IC902 change
X100 change
NO
NO
X300 14.318MHz
OK
IC301 change
IC301 (24-Pin)
66MHz OK
IC301 change
NO
J900 Connector
Power Cable Check
NO
IC914 change
YES
YES YES
YES
YES
C930 +1.15V OK
X100 32.768KHz
OK
IC301(49-pin)
133MHz OK
YES
YES
YES
IC301(10-pin)
33MHz OK
YES
YES
YES
YES
NO
NO
X300 change
R179,C210
Resoldeing

3-4
IC302(74-pin)
High=+3.3V OK
IC300(24-pin)
High=+3.3V OK
IC302(63-pin)
High=+3.3V OK
NO
Check IC104
R326 Re-soldering
NO
NO
NO
HDD Cables
Re-connection
R377, J302
Re-soldering
NO
IC302 change
HDD Cables
Connection OK
IC302(64-pin)
High=+3.3V OK
Change HDD
YESYES
YES
YES
YES
YES

3-5
3. VIDEO PART-1
No display
IC302(73-pin)
‘3.3V’=high OK
IC501(53-pin)
‘3.3V’= high OK
IC501(63-pin)
27MHz clock in OK
IC501(51,54-pin)
Clock in OK
NO
NO
NO
IC302 change
NO
OSC500 change
NO
Re-soldering
NO
R373 Re-soldering
YES
YES
YES
YES
YES
YES
YES YES
OSC500(3-pin)
27MHz clock out OK
YES
YES
R508 Re-soldering
IC103 check
IC501(44,45-pin)
I2C BUS OK NO
IC501(56-pin)
Clock out OK NO
Q504,Q505, R532 ~
R535 soldering OK
IC103 check
IC501 change
R521 ~ R524, L500
~ L503 Soldering OK
NO Re-soldering
C544 ~ C547,C560 ~
C563 Soldering OK
NO Re-soldering
Video Part OK
YES

3-6
4. YPBPR VIDEO OUTPUT TROUBLESHOOTING
No display
Cable connect
Video Cable
connection OK
S800 status OK
IC510(3,5-pin) Video
signal input OK
IC509,510 (8-pin)
+5V OK
NO
NO
NO
NO
S800 setting 480i
or 480p
NO Video Part-1 check
NO
Q815, R881 ~ 883,
R839 Check
Re-soldering
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
IC509(3-pin) Video
signal input OK
IC803 (4-pin)
Under +2.5V OK
IC803 Check
IC509,510 (4-pin)
-5V OK
IC509(1-pin) IC510(1,7-pin)
Video signal output OK
R774, R775, FL510,
FL512 Soldering OK
YPbPr
Video Output OK
NO
NONO
NO
J900 (3-pin) check
R740, R742, R745, R746, R762,
R765, R758 ,R759 soldering OK
IC510 Check
R738, R741,R743,
R744 soldering OK NO Re-soldering
IC509 Check
Re-soldering
Video Part-1 check