Mitsubishi Electric LT-40148 User manual

• Design specifications are subject to change without notice.
MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC.
9351JeronimoRoad,Irvine,CA 92618-1904
Copyright © 2008 Mitsubishi Digital ElectronicsAmerica, Inc.
AllRightsReserved
CAUTION:
Before servicing this chassis, it is important that the service person read the "SAFETY PRECAUTIONS" and
"PRODUCTSAFETYNOTICE" containedinthis manual.
SerSer
SerSer
Servicevice
vicevice
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ManualManual
ManualManual
Manual
2008
MITSUBISHIELECTRIC
LCD FLAT PANEL TELEVISION
VLP39+ / VLP39++ / VLP39+++ CHASSIS
•AVAnalog Inputs : VIDEOINJACK(RCAType)
& Outputs : AUDIOINJACK(RCAType)
: S-VIDEO IN JACK (Y/C separate)
: COMP/Y,Cr,Cb(RCAType)
: Stereo Audio Outputs
•Digital : HDMITM Inputs (digital)
Inputs/Outputs 480i, 480p, 720p, 1080i (60Hz)
1080p(24Hz, 30Hz, 60Hz)
: Digital Audio Output
(Dolby® Digital/PCM)
: USB Input (5 meg pixel photo)
•HDMITM DigitalPCCompatibilty
: 640 x 480, 898 x 480, 800 x 600,
1064 x 600, 1024 x768, 1280 x 720,
1365 x 768, 1280 x 1034 @ 60Hz
: 1920 x 1080 @ 24Hz, 30Hz, 60Hz
• Speakers : Two 5½"x2¼" Oval (4Ω 11W)
: 16 Projection Spkr Assy.
(VLP39++ Only)
: Lead-Free solder PWBs
VLP39+ Chassis
LT-40148
LT-46148
LT-52148
Pb Solder
Pb Solder
VLP39+++ Chassis
LT-46246 (LDTV-146)
LT-52246 (LDTV-152)
SPECIFICATIONS
• Power Input : AC 120V, 60Hz
•Power Usage : See table on page 5
• Dimensions : See table on page 5
& Weight
• LCD Panel : Resolution - 1920 x 1080
: Vertical Scan Rate - 120 Hz
• Tuning : Digital/Analog Tuner
(NTSC/ATSC/QAM)
: Out of Band Tuner
(VLP39++ & VLP+++ only)
• Tuning Range : Air VHF - 2~13, UHF - 14~69
Analog Cable - 1~125
Digital Cable - 1~135
•Antenna Input : 2 RF 75W unbalanced
VLP39++ Chassis
LT-46149
LT-52149
LT-46246

• TVGUIDEand otherrelated marks areregistered marks ofGemstar-TV
GuideInternational, Inc. and/or one of its affiliates.
• HDMI™is a trademark of HDMILicensing, LLC
• CableCARDisa trademark ofCableTelevisionLaboratories, Inc.
• Dolbyand Dolby digitalare registeredtrademarks of Dolby Laboratories.

Page 3
MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
INTRODUCTION ................................................................................................................................5
Dimensions,weight, powerusage, etc............................................................................................5
PRODUCTSAFETY NOTICE ............................................................................................................. 5
SAFETY PRECAUTIONS .................................................................................................................6
DISASSEMBLY ..................................................................................................................................7
LT-40148
BackCoverRemoval .......................................................................................................................7
LCDStandRemoval ........................................................................................................................7
Stand Holder,Stay-VESA-T&T-CONRemoval...............................................................................7
Chassis& Stay-VESA-B Removal ..................................................................................................8
Speaker,Switch,In/Out &PreampAssembliesRemoval.................................................................8
BezelRemoval ................................................................................................................................8
Holder-Panel-BottomRemoval.........................................................................................................9
Sides&ToppanelHolders, and Stay-PanelsR&LRemoval ............................................................9
Panel Installation in Bezel...............................................................................................................9
46” & 52” Models
BackCoverRemoval ..................................................................................................................... 10
Stand Removal .............................................................................................................................. 10
StandHolder Removal ................................................................................................................... 11 ,
Stay-VESA-T&ShieldT-CONRemoval......................................................................................... 11
Chassis& Stay-VESA-BRemoval ................................................................................................ 11
Speaker,Switch & In/OutAssemblies Removal............................................................................. 12
BezelRemoval .............................................................................................................................. 12
HolderPanelBottomRemoval....................................................................................................... 12
Side/TopHolderPanelsand Stay-PanelsRemoval ........................................................................ 13
Panel and/orBezel Replacement ..................................................................................................13
CHASSISDISASSEMBLY
IN/OUTCoverRemoval .................................................................................................................. 13
PWB-MAINCoverRemoval ........................................................................................................... 13
PWB-POWERRemoval ................................................................................................................ 14
PWB-MAINRemoval..................................................................................................................... 14
SBL,SPBOX& 16SPBOXAssemblies Removal ........................................................................... 15
LeadDress and ConnectorsLocations.......................................................................................... 16
SETUP,INTIALIZATION & ERROR CODES
UserControls and Inputs............................................................................................................... 19
OptionMenu ................................................................................................................................. 20
DigitalSignal Strength................................................................................................................... 20
Reset & Initialization ..................................................................................................................... 21
Initial Settings ............................................................................................................................... 22
AV Initial Settings ......................................................................................................................... 23
LED Diagnostics ........................................................................................................................... 23
ErrorCodesOperationalCheck..................................................................................................... 24
USINGLEAD FREE SOLDER .......................................................................................................... 25
CHIPPARTSREPLACEMENT ......................................................................................................... 26
REPLACEMENTPARTS .................................................................................................................. 27
PartsOrdering .............................................................................................................................. 27
Criticaland WarrantyParts Designation........................................................................................ 27
CONTENTS

Page 4
MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
PartsTolerance Codes.................................................................................................................. 27
Quick Reference List...................................................................................................................... 28
SERVICE PARTS LIST .................................................................................................................... 29
Stand Assembly Parts .................................................................................................................. 36
CIRCUITRYBLOCK DIAGRAMS ..................................................................................................... 37
MainPower Supply ....................................................................................................................... 37
PWB-DM DC to DC Supplies ........................................................................................................38
VideoSignal Path ......................................................................................................................... 39
AudioSignal Path ......................................................................................................................... 40
SoundProjector Block Diagram .................................................................................................... 41
OverallControlCircuitry ................................................................................................................ 42
AutoInput/Output Detect Circuitry ................................................................................................ 43
Short Protect Circuitry .................................................................................................................. 43
System 5 / Wired Remote I/O....................................................................................................... 44
SCHEMATICDIAGRAMS .....................................................................................................................

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 5
INTRODUCTION
Thisservice manual provides service instructions for LCD Flat Panel TV Models and Chassis:
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in television receivers have special safety related characteristics. These charac-
teristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by
usingreplacement componentsrated for higher voltage, wattage, etc.
Replacementparts which have special safety characteristics are identified in this service manual.
Electrical components having such features are identified by shading on the schematic diagram and parts list of this
service manual. Therefore, the replacement for any safety part should be identical in value and characteris-
tics.
Pb Solder
The PWBs used in the VLP39+,VLP39++ and V39+++ chassis are constructed using Lead-Free
solder. When servicing use only recommended Lead-Free solder (refer to page 25).
MODEL CHASSIS HEIGHT HEIGHT
w base WIDTH DEPTH DEPTH
w base WEIGHT w base POWER USAGE
LT-40148 VLP39+ 23.4" 25" 36.7" 4.9" 11.2" 51.8 lbs 250W
LT-46148 VLP39+ 26.4" 28" 42" 4.9" " 61.6 lbs 300W
LT-46149 VLP39++ 28.2" 29.9" " 4.9" 14.1" 71.6 lbs 315W
LT-46246 VLP39+++ 26.4" 28" " " 11.2" 61.6 lbs 315W
LT-52148 VLP39+ 29.6" 31.2" 47.7 " 14.1" 80.7 lbs 325W
LT-52149 VLP39++ 31.5" 33.3" " " " 83.6 lbs 330W
LT-52246 VLP39+++ 29.6" 31.2" " " " 80.7 lbs 330W
Product Dimensions & Weight
LT-46246

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 6
Leakage current check
Before returning the receiver to the customer, it is recommended that leakage current be measured according to the
followingmethods.
1. Cold Check
With the alternating current (AC) plug removed from the AC source, place a jumper across the two AC plug
prongs. Connect one lead of an ohm meter to the AC plug and touch the other lead to each exposed metal part
(i.e. antennas, handle bracket, metal cabinet, screw heads, metal overlay, control shafts, etc.), particularly any
exposed metal part that has a return path to the chassis. The resistance of the exposed metal parts having a
return path to the chassis should be a minimum of 1Meg Ohm. Any resistance below this value indicates an
abnormalconditionand requires correctiveaction.
2. Hot Check ...Use the circuit shown below to perform the hot check test.
1. Keep switch S1 open and connect the receiver to the measuring circuit. Immediately after
connection, andwith the switching devices of the receiver in their operating positions,measure the
leakage current for both positions of switch S2.
2. Close switch S1, energizing the receiver. Immediately after closing switch S1, and with the
switchingdevices of the receiver in their operating positions, measure the leakage current forboth
positions of switch S2. Repeat the current measurements of items 1 and 2 after the receiver has
reached thermal stabilization. The leakage current must not exceed 0.5 milliampere (mA).
SAFETY PRECAUTIONS
NOTICE: Observeall cautions andsafety related noteslocated inside thereceiver cabinet and on the receiver
chassis.
WARNING:
1. Operationof this receiver outside the cabinet or with the coverremoved presents a shock hazard from the
receiver's power supplies. Work on the receiver should not be attempted by anyone who is not thoroughly
familiarwith the precautions necessary when working onhigh voltage equipment.
2. Donot install, remove or handle the LCD panel in any manner unless shatterproof goggles areworn. People
not so equipped should be kept away while the panel is being handled. Keep the panel away from the body
whilehandling.
3. Whenservice is required, observe the original lead dress. Where a short-circuit has occurred, replace those
componentsthat indicate evidenceof overheating.
4. If the LCD Panel is damaged, crystalline liquid may leak from the LCD panel and broken glass may be
scattered. The crystalline liquid is toxic. Avoid contact with your skin, eyes, or mouth. DO NOT touch the
broken glass or crystalline liquid with bare hands, as cuts, poisoning, and/or skin irritation may occur. DO
NOT let glass fragments or crystalline liquid get into your eyes or mouth. Should either contact your eyes or
mouth, rinse the contacted area thoroughly with water and consult your doctor.
5. The fluorescent tubes in the panel contain mercury that is toxic and if broken should not be touched.
6. DO NOT dispose of the TV with general household waste. Follow local laws and regulations for legal and
safe disposal of theTV. For disposal or recycling information, contact local authorities or the Electronic
IndustriesAllianceat www.eiae.org.

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 7
Back Cover Removal Procedure
1) Removescrews (A) and (B) fromthe backcover.
2) Pull the back cover from theTV.
LT-40148 Disassembly
Stand Removal
1) Lay the unit face down on a soft flat surface.
2) Removescrews (C) from the stand and pull the
stand out the bottom of the unit.
1) Holder-Stand- screws(C).
2) STAY-VESA-T - screws (A).
3) SHIELD-TCON-screws (B).
Stand Holder, Stay-VESA-T & Shield T-CON Removal

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 8
Chassis & Stay-VESA-B Removal
1) Chassis - screws (C).
2) STAY-VESA-B-screws (D).
1) SpeakerAssy. - screws (D).
2) ASSY-SIDE-JACK - screw (E).
3) ASSY-SW-TOP- screws (F)
4) Preamp- screws(G).
Bezel Removal
1) Removescrews(H) from the
bottompanel.
2) Removescrew(J) from the
Bezel top.
3) Releasethesnapsandremove
the Bezel from the Panel.
Speaker, Switch, In/Out & PreampAssemblies Removal
LT-40148 Disassembly
(continued)

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 9
LT-40148 Disassembly
(continued)
Holder-Panel-Bottom Removal
Removescrews(H)to remove the
HOLDER-PANEL-BOTTOM
1) Holder-Panel-Top-screws (B).
2) Holder-Panel-Sides- screws (B).
3) Stay-Panels - screws (A).
Sides & Top Panel Holders, and Stay-Panels R&L Removal
Panel Installation in Bezel
1) ApplyDF-ADHESIVE-TAPEalongtheinside
top and sides of the Bezel.
2) ApplyDF-ADHESIVE-TAPE inside the
bottom of the Bezel.
3) Useeven pressure to install the LCD
Panel in the Bezel.

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 10
46” & 52” Models
Disassembly
46”
52”
Back Cover Removal Procedure
1) Removescrews (A) and (B) fromthe backcover.
2) Pull the back cover from theTV.
Stand Removal
1) Lay the unit face down on a soft flat surface.
2) Removescrews (C) fromthe stand and pull the stand out the bottom of the unit.
[InLT46149 &LT-52149removescrews (C) & (D)]

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 11
1) STAY-VESA-T-Remove screws (D).
2) Shield-TCON- Remove screws (F)and(G)..
Stay-VESA-T & Shield-T-CON Removal
Chassis & Stay-VESA-B Removal
1) Chassis- remove screws (E).
2) STAY-VESA-B - Removescrews (F).
46” & 52” Models
Disassembly (continued)
HolderStand-Removescrews (E).
Stand Holder Removal
52” Models
46” Models

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 12
46” & 52” Models
Disassembly (continued)
Bezel Removal
1) Removescrews (E) fromthe
bottompanel.
2) Removescrews(G) from the
Bezel top.
3) Releasethe snaps and
carefullyremovetheBezelfrom
thePanel.
1) SpeakerAssy. - remove screws (A).
2) ASSY-SIDE-JACK - screw (B).
3) ASSY-SW-TOP- screws (C)
Speaker, Switch, & In/OutAssy
Removal
Holder-Panel-Bottom
Removal
Removescrews(F) to remove the
HOLDER-PANEL-Bottom.

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 13
Panel or Bezel Replacement
Reversethe disassembly procedure to replace the LCD-PANELor Bezel.
NOTE:In models LT-46148and LT-52148installTAPE-LENSand DF-ADHESIVE-TAPEinside theBezel
beforemountingthe LCD-PANEL.(Refer topage9)
CHASSIS
Disassembly
IN/OUT Cover Removal
1) Removetwo nuts (A).
2) Removescrews(B) and (C).
3) RemoveIN/OUTcover.
PWB-MAIN Cover Removal
1) RemoveSCREWS(D).
2) Lift the cover from the chassis.
PWB-MAIN
COVER
Side/Top Holder Panels,
and Stay-Panels Re-
moval
1) Side & Top Holder Panels -
Screws (G) & (H 52” only).
2) Stay-Panels - Screws (J).

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 14
CHASSIS Disassembly
(continued)
PWB-POWER Removal
1) Removescrews(E).
2) Disconnectall interconnecting wiring..
3) Lift PWB-POWER from the chassis.
PWB-MAIN Removal
1) Removescrews(F).
2) Disconnectall interconnecting wiring..
3) Lift PWB-MAIN from the chassis.
PWB-MAIN
PWB-
POWER

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 15
SBL Assy
V39+++ Only
SPBOX Assy
V39+/V39+++ Only
16SPBOX Assy
V39++ Only

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 16
WIRE
CLAMPS
LEAD DRESS, CONNECTORS & WIRE CLAMPS
WhenreplacingtheLCDModule (Panel), the replacement paneldoesnotcome with the WireClampsattachedtothe panel.
Peel the backing off the clamps supplied with the panel, and place them at the locations indicated in the following diagram
for that specific model.
WIREDRESS LEGEND
Location toADD NEW Wire Clamp
Locationof REUSABLE Wire Clamp
MODEL PANEL WIRE CLAMP CLAMP (QTY)
LT-40148 289P120010 540D373010 8
LT-46148 289P121010 540D373010 10
LT-46149 289P121010 540D373010 11
LT-46246 289P121010 540D373010 14
LT-52148 289P122010 540D373010 12
LT-52149 289P122010 540D373010 13
LT-52246 289P122010 540D373010 18
LT-40148

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 17
LT-46148
LT-46149

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 18
LT-46246
LT-52148

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT-52149 / LT-52246
Page 19
LT-52149
LT-52246

MODELS: LT-40148 / LT-46148 / LT-46149 / LT-46246 / LT-52148 / LT 52149 / LT-52246
Page 20
REAR (Side) INPUTS
USER CONTROLS & INPUTS
Convenient Side Inputs
USER CONTROLS (Top)
Remote Control