Philips LCD1.20E Schematic

Colour Television

LCD1.20E

Contents Page

1 Technical Specifications, Connections,

and Chassis Overview 2 2 Safety Instructions, Warnings, and Notes 3 3 Directions for Use 6 4 Mechanical Instructions 8 5 Service Modes, Error messages,

and Repair Tips 9 6 Block Diagrams

Wiring Diagram 11

Block Diagram 11 7 Electrical Diagrams and PWB lay-outs Diagram PWB

Main Board 12-16 17-18

Control, Tuner, Speaker, and MX Panel 19 8 Electrical Alignments 21 9 Circuit Descriptions 23

Abbreviation List (N.A.)

IC Data Sheets (N.A) 10 Spare Parts List 24 11 Revision List 26

Copyright 2003 Philips Consumer Electronics B.V. Eindhoven, The Netherlands. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise without the prior permission of Philips.

Published by LM 0369 Service PaCE Printed in the Netherlands Subject to modification EN 3122 785 12521

EN 2 LCD1.20E1.

Technical Specifications, Connections, and Chassis Overview

1. Technical Specifications, Connections, and Chassis Overview

1.1 Technical Specifications

1.1.1 Reception

Tuning system : PLL Colour systems : PAL B/G,

: PAL D/K, : PAL I : SECAM B/G, : SECAM D/K, : SECAM L, : SECAM L1, : NTSC Play Back

Sound systems : 2CS B/G,

Frequency bands : VHF,

Channel selections : 100 channels Aerial input : 75 ohm

: 2CS D/K, : AV Stereo, : NICAM B/G : (5.5-5.85), : NICAM D/K

: UHF, : S-Channel, : Hyperband

1.1.2 LCD Characteristics

Type : LCD XGA TFT Size : 20 inch (51 cm) Pixel format : 640x480 pixels

1.1.3 Optical Characteristics

Contrast ratio : 400:1 (typ.) Brightness : 450 cd/m2 typ. Viewing Angle : 140x120 deg. (HxV)

1.1.4 Audio

Speakers : Full range

1.1.5 Miscellaneous

Power consumption

Normal operation : 70 W Standby : 3 W

Power Supply

Power Adaptor

Input : AC 95 to 264 V, 50/60

Output : DC 12 V, 3 A

: 2 x 2 W_rms

Environment

Ambient temperature : +5 to +40 deg. C Relative humidity : 10% to 80% R.H.

Weight : 9 kg Dimension (WxHxD) : 642x423x83 m

Safety Instructions, Warnings, and Notes

2. Safety Instructions, Warnings, and Notes

EN 3LCD1.20E 2.

2.1 Safety Instructions

• Always connect the TV set via an Insulation transformer. Use a transformer of adequate power to protect the technician from injury by electrical shocks. It will also protect the TV set and it's components from being damaged by accidental shorts of the circuitry, which may be occurred during the service operation.

• Replace safety components, indicated by the symbol i in the Schematic diagram and Replacement parts list, only by the identical components to the original ones. Any other component substitution (other than original type) may increase risk of fire or electrical shock hazard.

• If any fuse (or Fusible resistor) in this TV set is blown, replace it as specified.

• While 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.

2.1.1 AC Leakage Current Check

Before returning the TV set 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 by electrical shock.

Leakage Current Cold Check (Antenna Cold Check)

1. Unplug the AC cord, and connect an electrical jumper between the two plug prongs of the AC cord.

2. Turn “on” the AC power switch (keep the AC cord unplugged!).

3. Measure the resistance value between the plug prongs of the AC cord and the metal shielding of the tuner or the aerial connection of the TV set. The measured resistance should be between 1 Mohm and 5.2 Mohm. When the metal shielding has no return path to the chassis, the measured resistance must be infinite.

4. Switch the TV set “off’” and remove the electrical jumper between the two plug prongs of the AC cord.

5. Check the cabinet for defects, to prevent the possibility of the customer touching any internal parts.

Leakage Current Hot Check

1. Plug the AC cord directly into the AC outlet.

2. Connect 1.5 kohm/10 W resistor in parallel with a 0.15 uF

capacitor between a good known earth ground (Water Pipe, Conduit, etc.) and the exposed metallic parts.

3. Measure the AC voltage across the resistor, using the AC voltmeter with 1000 ohm/V or higher sensitivity.

4. Plug again 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 V_rms, which corresponds to 0.5 mA.

5. If any measurement is out of the specified limits, there is a possibility of a shock hazard, and the set must be checked and repaired before returning to the customer.

2.2 Warnings:

Before servicing TV sets, covered by this service manual and its supplements and addenda, read and follow the Safety Instructions of this manual.

Note: If unforeseen circumstances create conflict between the following Servicing Precautions and any of the Safety Instructions of this manual, always follow the Safety Instructions. Remember: Safety First.

2.2.1 General Servicing Precautions

1. Always unplug the TV set AC power cord from the AC power source before:

1. Removing or reinstalling any component, circuit board

module, or any other receiver assembly;

2. Disconnecting or reconnecting any TV set electrical

plug or other electrical connection;

3. Connecting a test substitute in parallel with an

electrolytic capacitor in the receiver. Caution: A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result to an explosion hazard.

2. Test high voltage only by measuring it with an appropriate high voltage meter or other voltage measuring device (DVM, FETVOM, etc), equipped with a suitable high voltage probe. Do not test high voltage by "drawing an arc".

3. Do not spray chemicals on or near this TV set or any of its assemblies.

4. Unless specified otherwise in this service manual, clean electrical contacts only by applying the following mixture to the contacts with a pipe cleaner, cotton-tipped stick or comparable nonabrasive applicator; 10% (by volume) Acetone and 90% (by volume) Isopropyl alcohol (90%-99% strength). Caution: This is a flammable mixture.

5. Unless specified otherwise in this service manual, lubrication of contacts in not required.

6. Do not defeat any plug/socket B+ voltage interlocks, with which the TV sets might be equipped.

7. Do not apply AC power to this TV set and/or any of its electrical assemblies, unless all solid-state device heat sinks are correctly installed.

8. Always connect the test TV set ground lead to the TV set chassis ground before connecting the test TV set positive lead.

9. Always remove the test TV set ground lead last.

10. Use with this TV set only the test fixtures, specified in this

service manual.

Figure 2-1 Leakage current hot check circuit

Note: Do not use a line Insulation transformer during this

check.

Caution: Do not connect the test fixture ground strap to any heat sink in this TV set.

EN 4 LCD1.20E2.

Safety Instructions, Warnings, and Notes

2.2.2 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 to reduce the incidence of component damage, caused by static electricity.

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed to prevent 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 aluminium foil, to prevent electrostatic charge build-up 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 type 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 electrical charges, sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective package, until immediately before you are ready to install it. (Most replacement ES devices are packed r with leads electrically shorted together by conductive foam, aluminium 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. (Otherwise harmless motion, such as the brunching together of your clothes fabric or the lifting of your foot from a carpeted floor, can generate static electricity, sufficient to damage an ES device).

2.2.3 General Soldering Guidelines

1. Use a grounded-tip, low-wattage soldering iron and appropriate tip size and shape, that will maintain tip temperature within the range of 500 deg. F to 600 deg. F.

2. Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts lead.

3. Keep the soldering iron tip clean and well tinned.

4. Thoroughly clean the surfaces to be soldered. Use a small

wire-bristle brush (0.5 inch or 1.25cm) with a metal handle. Do not use freon-propelled spray-on cleaners.

5. Use the following unsoldering technique:

1. Allow the soldering iron tip to reach normal

temperature (500 deg. F to 600 deg. F).

2. Heat the component lead until the solder melts.

3. Quickly draw the melted solder with an anti-static,

suction-type solder removal device or with solder braid. Caution: Work quickly to avoid overheating the circuit board printed foil.

6. Use the following soldering technique:

1. Allow the soldering iron tip to reach the normal

temperature (500 deg. F to 600 deg. F).

2. First, hold the soldering iron tip and solder the strand

against the component lead until the solder melts.

3. Quickly move the soldering iron tip to the junction of the

component lead and the printed circuit foil, and hold there only until the solder flows onto and around of the both of the component lead and the printed circuit foil.

Caution: Work quickly to avoid overheating the circuit board printed foil.

4. Closely inspect the solder area and remove any excess or splashed solder with a small wire-bristle brush.

2.3 Maintenance Instructions

2.3.1 IC Remove/Replacement

Some chassis circuit boards have slotted holes (oblong), through which the IC leads are inserted and then bent flat against the circuit foil. When holes are the slotted type, the following technique should be used to remove and replace the IC.

Removal

1. Desolder and straighten each IC lead in one operation, by gently prying up the lead with the soldering iron tip, as the solder melts.

2. Draw away the melted solder with an anti-static suction type solder removal device (or with solder braid) before removing the IC.

Replacement

1. Carefully insert the replacement IC in the circuit board.

2. Carefully bend each IC lead against the circuit foil pad and

solder it.

3. Clean the soldered areas with a small wire-bristle brush. It is not necessary to reapply acrylic coating to the areas.

2.3.2 "Small-Signal" Discrete Transistor Removal/ Replacement

1. Remove the defective transistor by clipping its leads as close as possible to the component body.

2. Bend into a "U" shape the end of each of three leads, remaining on the circuit board.

3. Bend into a "U" shape the replacement transistor leads.

4. Connect the replacement transistor leads to the

corresponding leads, extending from the circuit board, and crimp the "U" with long nose pliers to insure metal to metal contact. Then solder each connection.

2.3.3 Power Output, Transistor Device Removal/ Replacement

1. Heat and remove all solder all around from the transistor leads.

2. Remove the heat sink mounting screw (if so equipped).

3. Carefully remove the transistor from the heat sink of the

circuit board.

4. Insert a new transistor in the circuit board.

5. Solder each transistor lead, and clip off excess lead.

6. Replace the heat sink.

2.3.4 Diode Removal/ Replacement

1. Remove defective diode by clipping its leads as close as possible to diode body.

2. Bend the two remaining leads perpendicular to the circuit board.

3. Observing diode polarity, wrap each lead of the new diode around the corresponding lead on the circuit board.

4. Securely crimp each connection and solder it.

5. Inspect (on the circuit board copper side) the solder joints

of the two "original" leads. If they are not shiny, reheat them and, if necessary, apply additional solder.

2.3.5 Fuse and Conventional Resistor Removal/ Replacement

1. Clip each fuse or resistor lead at the top of the circuit board hollow stake.

Safety Instructions, Warnings, and Notes

EN 5LCD1.20E 2.

2. Securely crimp the leads of replacement component around notch at stake top.

3. Solder the connections.

Caution: Maintain original spacing between the replaced component and adjacent components and the circuit board to prevent excessive component temperatures.

2.3.6 Circuit Board Foil Repair

Excessive heat applied to the copper foil of any printed circuit board will weaken the adhesive that bonds the foil to the circuit board, causing the foil to separate from or "lift-off" the board. The following guidelines and procedures should be followed whenever this condition is encountered.

At IC Connections

To repair a defective copper pattern at IC connections, use the following procedure to install a jumper wire on the copper pattern side of the circuit board. (Use this technique only on IC connections).

1. Carefully remove the damaged copper pattern with a sharp knife. (Remove only as much copper as absolutely necessary).

2. Carefully scratch away the solder resist and acrylic coating (if used) from the end of the remaining copper pattern.

3. Bend a small "U" in one end of a small gauge jumper wire and carefully crimp it around the IC pin. Solder the IC connection.

4. Route the jumper wire along the path of the out-away copper pattern and let it overlap the previously scraped end of the good copper pattern. Solder the overlapped area and clip off any excess jumper wire.

2.4 Notes

2.4.1 Schematic Notes

• All resistor values are in ohms and the value multiplier is often used to indicate the decimal point location (e.g. 2K2 indicates 2.2 kohm).

• Resistor values with no multiplier may be indicated with either an "E" or an "R" (e.g. 220E or 220R indicates 220 ohm).

• All capacitor values are expressed in micro-farads (µ= x 10^-6), nano-farads (n= x 10^-9), or pico-farads (p= x 10^-

12).

• Capacitor values may also use the value multiplier as the decimal point indication (e.g. 2p2 indicates 2.2 pF).

• An "asterisk" (*) indicates component usage varies. Refer to the diversity tables for the correct values.

• The correct component values are listed in the Electrical Replacement Parts List. Therefore, always check this list when there is any doubt.

At Other Connections

Use the following technique to repair the defective copper pattern at connections, other than IC Pins. This technique involves the installation of a jumper wire on the component side of the circuit board.

1. Remove the defective copper pattern with a sharp knife. Remove at least 1/4 inch of copper, to ensure that a hazardous condition will not exist if the jumper wire opens.

2. Trace along the copper pattern from both sides of the pattern break and locate the nearest component that is directly connected to the affected copper pattern.

3. Connect insulated 20-gauge jumper wire from the lead of the nearest component on one side of the pattern break to the lead of the nearest component on the other side.

4. Carefully crimp and solder the connections.

Caution: Be sure the insulated jumper wire is dressed so it does not touch components or sharp edges.

EN 6 LCD1.20E3.

AUTO

Y-Z

‡

†

LIST

V Volum e

Press + or - to adjust the

vo lum e.

¬ Mute

Tem porarily interrupt the

sound or restore it.

P Programme selection

•to brow se through the TV

channels which are no t

skipped

•to sw itch the TV on fro m

standb y.

®Ò‡π† Video

reco rd er keys

U Time disp lay

The time,downloaded fro m the

TV channel (with teletext

broadcast) stored on

programme num ber 1 or the

low est not sk ipped programme

num ber,is displayed on the

screen.

0/9Digit keys

To select a TV channel.

0 Previous programme

To disp lay the previously

selectedTV channel.

LIST

Programme list

To disp lay the programme list.

b Teletext on/off

Teletext functions

hUfgcek

Sleep timer

With this key you can set a

time period after which the

TV sho uld sw itch itself to

standb y.

Press the key rep e atedly to

select the num ber of minutes.

The counter runs fro m B 0,

10,20,30...to 240 minutes.

The timer begins to count

dow n fro m the num ber of

minutes selected.

Note:To view the rem aining time,

pre ss the

key once.To can cel

the sleep time,repeatedly press

the

key until B 0 appears.

Press rep e a tedly to

display each menu.

O K Press this key to activate

yo ur cho ice,w hen in the menus.

3. Directions for Use

Directions for Use

picture

keys

AUTO

and sound se ttings.

To select predefined picture

AUTO

standb y or off to standb y.

Sw itche s the TV on fro m

B Standby

AUTO

Y-Z

selected,corresponding with

different picture se tting is

Each time it is pre ssed,a

LIST

sound

AUTO

Contrast,Brigh tne ss,C o lour

and Sharpness.

spe c ific factory settings of

different sound se tting is

Each time it is pre ssed,a

refers to the personal

in the picture and sound menu.

and sound se lected an d stored

preference se ttings of picture

treb le an d bass.

selected,corresponding with

spe c ific factory settings of

Perso nal

‡

†

DESCRIPTION OF CONTROLS

AV1,AV2,S-VIDEO

Source

peripherals:p re ss rep e atedly to

select

Select you r com puter or other

monitor mode.

X Bilingual cho ice an d

Nicam

Stereo

sound in case of

Mono

Nicam Stereo

stereo tran sm ission,or fro m

• to sw itch fro m

Press this key

sound mode selection

,in case of digital

Mono

tran sm ission

lY,

Dua

Z or

Nicam Dual

• to sw itch fro m

X in case

X in case of

Dual

Z or

Nicam Dual

Y to

Nicam Dual

Y se nd s the primary

of bilingual tran sm ission:

Dual

Nicam Dual tran sm ission

broadcast language to the

• to choose betw een

Z se nd s the seco n d ar y

loudspeakers;

Dual

loudspeakers;

broadcast language to the

X se nd s a se p ara te

Dual

lan guage to each loudspeaker.

Nica m stereo transm ission,select

sound sign als,w ith stereo or

Note:in case of weak stereo

fro m the aud io R input to the righ t loudspeaker

•R+R:the audio sign al fro m the au d io R input is se nt to the left and right loudspeakers.

•L+L:the audio sign al fro m the au d io L input is sent to the left an d righ t loudspeakers

•L+R:the audio signal fro m the au d io L input is sent to the left loudspeaker,the au dio signal

Press the X ke y rep e atedly to select:

Sound output se lection in AV mode

mono reception.

In AV mode,you can select the output sound for the left and right loudspeakers.

Directions for Use

EN 7LCD1.20E 3.

Personal Notes:

ON/OFF

CH/PR

VOL

TV/VIDEO MENU

monitor mode

key to sw itch the TV on or off

ON/OFF

:P ress the power

in fro nt of the TV.

Sho uld your rem o te co n trol be lost or bro ken yo u can still operate yourTV with the keys

ON/OFF

:Keep the OK key p re ssed for abo u t 10 sec o n d s.

:P ress rep e atedly to select

Auto dem onstration

All the menus are being disp layed autom atically one after the other.

To stop Auto dem o nstratio n ,p re ss any key on the fro n t panel.

:P ress rep e atedly to display each menu

TV/VIDEO

OK: - P re ss this key to activate yo ur cho ice when in the menu

:- P ress - or + to brow se through the TV channels which are not sk ipped;

- Pre ss - or + to adjust the menu settings.

- Pre ss - or + to adjust the vo lum e;

:- P ress - or + to select a menu item ;

-V O L +

- CH /PR +

sw itch ed on.

-To sw itch the TV on fro m standb y.

- Pre ss - or + to select a menu item ;

TheB indicator ligh ts up brigh tly when the TV is in standby,dims when the TV is

B:Switches the TV on fro m stan db y or off to standb y.

EN 8 LCD1.20E4.

Mechanical Instructions OLD!!!!

4. Mechanical Instructions OLD!!!!

Notes:

• To gain access to the boards of the TV set, after removing the cover cup, unstick carefully supportive stickers.

• Place the stickers aside, adhesive side upwards.

• When you re-assemble the TV set, don’t forget to put the

stickers back.

• If the stickers are not adhesive anymore, you can order them by ordering number 3104 301 24501

+ 18 hidden pages