Toshiba 20A46C Service Manual
FILE NO. 050-200615GR
(MFR’S VERSION A)
SERVICE MANUAL
COLOR TELEVISION
20A46C
The above model is classified as a green product (*1), as indicated by the underlined serial number.
This Service Manual describes replacement parts for the green product. When repairing this green
product, use the part(s) described in this manual and lead-free solder (*2).
For (*1) and (*2), see the next page.
DOCUMENT CREATED IN JAPAN, March, 2006
(*1) GREEN PRODUCT PROCUREMENT
The EC is actively promoting the WEEE & RoHS Directives that define standards for recycling
and reuse of Waste Electrical and Electronic Equipment and for the Restriction of the use of
certain Hazardous Substances. From July 1, 2006, the RoHS Directive will prohibit any
marketing of new products containing the restricted substances.
Increasing attention is given to issues related to the global environmental. Toshiba Corporation
recognizes environmental protection as a key management tasks, and is doing its utmost to
enhance and improve the quality and scope of its environmental activities. In line with this,
Toshiba proactively promotes Green Procurement, and seeks to purchase and use products,
parts and materials that have low environmental impacts.
Green procurement of parts is not only confined to manufacture. The same green parts used in
manufacture must also be used as replacement parts.
(*2) LEAD-FREE SOLDER
This product is manufactured using lead-free solder as a part of a movement within the consumer
products industry at large to be environmentally responsible. Lead-free solder must be used in
the servicing and repair of this product.
WARNING
This product is manufactured using lead free solder .
DO NOT USE LEAD BASED SOLDER TO REPAIR THIS PRODUCT !
The melting temperature of lead-free solder is higher than that of leaded solder by 86°F to 104°F
(30°C to 40°C). Use of a soldering iron designed for lead-based solders to repair product made
with lead-free solder may result in damage to the component and or PCB being soldered. Great
care should be made to ensure high-quality soldering when servicing this product especially
when soldering large components, through-hole pins, and on PCBs as the level of heat
required to melt lead-free solder is high.
A1-1
SERVICING NOTICES ON CHECKING
As for the places which need special attentions,
they are indicated with the labels or seals on the
cabinet, chassis and parts. Make sure to keep the
indications and notices in the operation manual.
2. AVOID AN ELECTRIC SHOCK
There is a high voltage part inside. Avoid an
electric shock while the electric current is
flowing.
3. USE THE DESIGNATED PARTS
The parts in this equipment have the specific
characters of incombustibility and withstand
voltage for safety. Therefore, the part which is
replaced should be used the part which has
the same character.
Especially as to the important parts for safety
which is indicated in the circuit diagram or the
table of parts as a mark, the designated
parts must be used.
4. PUT PARTS AND WIRES IN THE
ORIGINAL POSITION AFTER
ASSEMBLING OR WIRING
There are parts which use the insulation
material such as a tube or tape for safety, or
which are assembled in the condition that
these do not contact with the printed board.
The inside wiring is designed not to get closer
to the pyrogenic parts and high voltage parts.
Therefore, put these parts in the original
positions.
5. TAKE CARE TO DEAL WITH THE
CATHODE-RAY TUBE
In the condition that an explosion-proof cathoderay tube is set in this equipment, safety is
secured against implosion. However, when
removing it or serving from backward, it is
dangerous to give a shock. Take enough care to
deal with it.
6. AVOID AN X-RAY1. KEEP THE NOTICES
Safety is secured against an X-ray by considering about the cathode-ray tube and the high
voltage peripheral circuit, etc.
Therefore, when repairing the high voltage peripheral circuit, use the designated parts and
make sure not modify the circuit.
Repairing except indicates causes rising of high
voltage, and it emits an X-ray from the cathoderay tube.
PERFORM A SAFETY CHECK AFTER
7.
SERVICING
Confirm that the screws, parts and wiring which
were removed in order to service are put in the
original positions, or whether there are the
portions which are deteriorated around the
serviced places serviced or not. Check the
insulation between the antenna terminal or
external metal and the AC cord plug blades.
And be sure the safety of that.
(INSULATION CHECK PROCEDURE)
1.
Unplug the plug from the AC outlet.
2.
Remove the antenna terminal on TV and turn
on the TV.
3.
Insulation resistance between the cord plug
terminals and the eternal exposure metal
[Note 2] should be more than 1M ohm by
using the 500V insulation resistance meter
[Note 1].
4.
If the insulation resistance is less than 1M
ohm, the inspection repair should be
required.
[Note 1]
If you have not the 500V insulation
resistance meter, use a Tester.
[Note 2]
External exposure metal: Antenna terminal
Earphone jack
HOW TO ORDER PARTS
Please include the following informations when you order parts. (Particularly the VERSION LETTER.)
1. MODEL NUMBER and VERSION LETTER
The MODEL NUMBER can be found on the back of each product and the VERSION LETTER can be
found at the end of the SERIAL NUMBER.
2. PART NO. and DESCRIPTION
You can find it in your SERVICE MANUAL.
IMPORTANT
Inferior silicon grease can damage IC's and transistors.
When replacing an IC's or transistors, use only specified silicon grease (YG6260M).
Remove all old silicon before applying new silicon.
A1-2
TABLE OF CONTENTS
GREEN PRODUCT PROCUREMENT .......................................................................................
LEAD-FREE SOLDER ................................................................................................................
SERVICING NOTICES ON CHECKING.....................................................................................
HOW TO ORDER PARTS ..........................................................................................................
IMPORTANT ...............................................................................................................................
TABLE OF CONTENTS..............................................................................................................
GENERAL SPECIFICATIONS ...................................................................................................
DISASSEMBLY INSTRUCTIONS
1. REMOVAL OF ANODE CAP ...............................................................................................
2. REMOVAL AND INSTALLATION OF FLAT PACKAGE IC ................................................
SERVICE MODE LIST ................................................................................................................
CONFIRMATION OF HOURS USED .........................................................................................
WHEN REPLACING EEPROM (MEMORY) IC ..........................................................................
ELECTRICAL ADJUSTMENTS..................................................................................................
BLOCK DIAGRAMS ...................................................................................................................
PRINTED CIRCUIT BOARDS
MAIN/CRT................................................................................................................................
SCHEMATIC DIAGRAMS
MICON/CHROMA/TUNER ......................................................................................................
DEFLECTION/CRT..................................................................................................................
POWER ...................................................................................................................................
SOUND ....................................................................................................................................
AV ............................................................................................................................................
WAVEFORMS .............................................................................................................................
MECHANICAL EXPLODED VIEWS...........................................................................................
MECHANICAL REPLACEMENT PARTS LIST .........................................................................
ELECTRICAL REPLACEMENT PARTS LIST...........................................................................
A1-1
A1-1
A1-2
A1-2
A1-2
A2-1
A3-1~A3-5
B1-1
B2-1, B2-2
C-1
C-1
C-1
D-1~D-5
E-1, E-2
F-1~F-4
G-1, G-2
G-3, G-4
G-5, G-6
G-7, G-8
G-9, G-10
H-1, H-2
I-1, I-2
J1-1
J2-1~J2-3
A2-1
GENERAL SPECIFICATIONS
G-1 TV CRT CRT Size / Visual Size 20 inch / 508.0mmV
G-2 Tuning Broadcasting System US System M
G-3 Power Power Source AC 120V AC 60Hz
G-4 Regulation Safety CSA
G-5 Temperature Operation +5oC ~ +40oC
G-6 Operating Humidity Less than 80% RH
System CRT Type Normal
Color System NTSC
Speaker 2Speaker
Sound Output MAX
NTSC3.58+4.43 /PAL60Hz No
System Tuner and System 1Tuner
Receive CH Destination USA(W/ CABLE)
Intermediate Picture(FP) 45.75MHz
Frequency Sound(FS) 41.25MHz
Preset CH No
Stereo/Dual TV Sound Yes
Tuner Sound Muting Yes
Power Consumption at AC
Protector Power Fuse Yes
Magnetic Field BV/BH +0.45G/0.18G
Position Front
Size
Impedance 8 ohm
10%(Typical) - W
CH Coverage A - I, J - W, W+1 - W+84
FP-FS 4.50MHz
DC
Stand by (at AC)
Per Year
Radiation IC
X-Radiation HWC
Storage -20oC ~ +60oC
2 x 4.7 Inch
2.5+2.5 W
90 W at AC 120 V 60 Hz
5 W at AC 120 V 60 Hz
-- kWh/Year
2 - 69, 4A, A-5 - A-1,
A3-1
GENERAL SPECIFICATIONS
G-7 On Screen Menu Yes
G-8 OSD Language English French Spanish
Display Menu Type Character
Picture Yes
Contrast Yes
Brightness Yes
Color Yes
Tint Yes
Sharpness Yes
Audio No
Bass No
Treble No
Balance No
BBE On/Off No
Stable Sound On/Off No
Surround On/Off No
CH Set Up Yes
TV/CABLE(CATV) Yes
Auto CH Memory Yes
Add/ Delete Yes
Lock Yes
CH Lock Yes
Video Lock Yes
Game Timer Yes
Change Password Yes
On Timer Yes
Language Yes
V-chip No
CH Label No
Favorite CH No
Color Stream DVD/DTV No
Control Level Yes
Volume Yes
Brightness Yes
Contrast Yes
Color Yes
Tint Yes
Sharpness Yes
Tuning No
Bass No
Treble No
Balance No
Stereo,Audio Output,SAP Yes
Video Yes
Color Stream No
Channel(TV/Cable) Yes
CH Label No
Game Timer Yes
Sleep Timer Yes
Sound Mute Yes
V-chip Rating No
16: 9 No
G-9 Clock and Sleep Timer Max Time 120 Min
Timer Step 10 Min
On Timer Program(On Timer ) Yes
Wake Up Timer No
Timer Back-up (at Power Off Mode) more than -- Min Sec
A3-2
GENERAL SPECIFICATIONS
G-10 Remote Unit RC-EH
Control Glow in Dark Remocon Yes
Format Toshiba
Remocon Format Toshiba
Custom Code
Power Source Voltage(D.C) 3V
UM size x pcs UM-4 x 2 pcs
Total Keys 28 Keys
Keys Power Yes
1 Yes
2 Yes
3 Yes
4 Yes
5 Yes
6 Yes
7 Yes
8 Yes
9 Yes
0 Yes
100 No
CH Up Yes
CH Down Yes
Volume Up Yes
Volume Down Yes
TV/Caption/Text Yes
CH1/CH2 Yes
TV/Video(TV/AV) Yes
CH RTN/CH ENT(Quick View) Yes
Sleep Yes
RE Call(Call) Yes
Reset Yes
Menu Yes
Enter Yes
Mute Yes
Exit No
MTS(Audio Select) Yes
Set + Yes
Set - Yes
16: 9 No
Multi Brand Keys CH Up(VCR) No
CH Down(VCR) No
Pause/Still No
TV/VCR(VCR) No
Code No
FF No
Rew No
Rec No
Play No
Stop No
TV No
VCR No
Cable No
40-BF h
A3-3
GENERAL SPECIFICATIONS
G-11 Features Auto Degauss Yes
G-12 Accessories Owner's Manual Language English / French
Auto Shut Off Yes
Canal+ No
Cable Yes
Anti-theft No
Rental No
Memory(Last CH) Yes
Memory(Last Volume) Yes
V-Chip No
BBE No
Auto Search No
CH Allocation No
SAP Yes
Just Clock Function No
CH Label No
VM Circuit No
Full OSD No
Premiere No
Comb Filter No
Auto CH Memory Yes
Hotel Lock No
Closed Caption Yes
Stable Sound No
FBT Leak Test Protect Yes
CH Lock Yes
Video Lock Yes
Game Timer Yes
Energy Star No
Favorite CH No
Surround No
16:9 Mode No
Remote Control Unit Yes
Rod Antenna No
Loop Antenna
U/V Mixer
DC Car Cord (Center+)
Guarantee Card
Warning Sheet
Circuit Diagram
Antenna Change Plug
Service Facility List
Important Safety Instruction
Dew/AHC Caution Sheet
AC Plug Adapter
Quick Set-up Sheet
Battery Yes
AC Cord
AV Cord (2Pin-1Pin)
Registration Card (NDL Card)
ESP Card
PTB Sheet
300 ohm to 75 ohm Antenna Adapter
Type -- Type
Lines
W/ Warranty Yes
Poles
Terminal
Terminal
UM size x pcs UM4 x 2
OEM Brand
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
A3-4
GENERAL SPECIFICATIONS
G-13 Interface Switch Front Power Yes
Rear AC/DC No
Indicator Power Yes(RED)
Terminals Front Video Input
Rear Video Input(Rear1)
G-14 Set Size Approx. W x D x H (mm)
G-15 Weight Net (Approx.)
G-16 Carton Master Carton
Gift Box Material Double/Brown
Drop Test
Container Stuffing
G-17 Cabinet Material Cabinet Cabinet Front PS 94V0 DECABROM
PCB Non-Halogen Demand
G-18 Environment Environmental standard requirement (by buyer) Green procurement of TOSHIBA
System Select No
Main Power SW No
Sub Power No
Channel Up/Reset Yes
Channel Down/Enter Yes
Volume Up/Set Up Yes
Volume Down/Set Down Yes
MENU=Volume Up+Volume Down Yes
TV/CATV Selector No
Degauss No
Main Power SW No
Stand-by No
On Timer No
Audio Input
Other Terminal
Video Input(Rear2)
Audio Input(Rear1)
Audio Input(Rear2)
Video Output
Audio Output
Euro Scart
Color Stream
Diversity No
Ext Speaker No
DC Jack 12V(Center +) No
VHF/UHF Antenna Input
AC Outlet No
Gross (Approx.)
Content ----
Material --
Dimensions W x D x H(mm) -- x -- x --
Description of Origin
Dimensions W x D x H(mm) 658 x 575 x 529
Description of Origin Yes
Height (cm) 60 (ORION SPEC:46)
Cabinet Rear PS 94V0 DECABROM
Eyelet Demand Yes
Pb-free Phase3(Phase3A)
RCA
RCA x 2(L/MONO,R)
Head phone
RCA
RCA x 2(L/MONO,R)
F Type
590 x 492 x 446.5
21.0kg
23.8kg
Natural Dropping At 1 Corner / 2 Edges /
288
No
No
No
No
No
No
( 46.3 lbs)
( 52.5 lbs)
No
Sets
/--
No
4 Surfaces
Sets/40' container
No
A3-5
DISASSEMBLY INSTRUCTIONS
1. REMOVAL OF ANODE CAP
Read the following NOTED items before starting work.
*
After turning the power off there might still be a potential
voltage that is very dangerous. When removing the
Anode Cap, make sure to discharge the Anode Cap's
potential voltage.
*
Do not use pliers to loosen or tighten the Anode Cap
terminal, this may cause the spring to be damaged.
REMOVAL
1. Follow the steps as follows to discharge the Anode Cap.
(Refer to Fig. 1-1.)
Connect one end of an Alligator Clip to the metal part of a
flat-blade screwdriver and the other end to ground.
While holding the plastic part of the insulated Screwdriver,
touch the support of the Anode with the tip of the
Screwdriver.
A cracking noise will be heard as the voltage is discharged.
GND on the CRT
3. After one side is removed, pull in the opposite direction to
remove the other.
NOTE
Take care not to damage the Rubber Cap.
INSTALLATION
1. Clean the spot where the cap was located with a small
amount of alcohol. (Refer to Fig. 1-3.)
Location of Anode Cap
Fig. 1-3
NOTE
Confirm that there is no dirt, dust, etc. at the spot where
the cap was located.
2.3.Arrange the wire of the Anode Cap and make sure the
wire is not twisted.
Turn over the Rubber Cap. (Refer to Fig. 1-4.)
Screwdriver
Alligator Clip
GND on the CRT
Flip up the sides of the Rubber Cap in the direction of the
2.
arrow and remove one side of the support.
(Refer to Fig. 1-2.)
Rubber Cap
CRT
Support
Support
CRT
Fig. 1-1
Fig. 1-2
4. Insert one end of the Anode Support into the anode button,
then the other as shown in Fig. 1-5.
Support
CRT
5.6.Confirm that the Support is securely connected.
Put on the Rubber Cap without moving any parts.
B1-1
Fig. 1-4
Fig. 1-5
DISASSEMBLY INSTRUCTIONS
2.
REMOVAL AND INSTALLATION OF
FLAT PACKAGE IC
REMOVAL
Put the Masking Tape (cotton tape) around the Flat
1.
Package IC to protect other parts from any damage.
(Refer to Fig. 2-1.)
NOTE
Masking is carried out on all the parts located within 10
mm distance from IC leads.
When IC starts moving back and forth easily after
3.
desoldering completely, pickup the corner of the IC using a
tweezers and remove the IC by moving with the IC
desoldering machine. (Refer to Fig. 2-3.)
NOTE
Some ICs on the PCB are affixed with glue, so be
careful not to break or damage the foil of each IC leads
or solder lands under the IC when removing it.
Blower type IC
desoldering
machine
Masking Tape
(Cotton Tape)
Heat the IC leads using a blower type IC desoldering
2.
IC
machine. (Refer to Fig. 2-2.)
NOTE
Do not add the rotating and the back and forth
directions force on the IC, until IC can move back and
forth easily after desoldering the IC leads completely.
Blower type IC
desoldering machine
Fig. 2-1
Tweezers
IC
Peel off the Masking Tape.4.
Absorb the solder left on the pattern using the Braided
5.
Shield Wire. (Refer to Fig. 2-4.)
NOTE
Do not move the Braided Shield Wire in the vertical
direction towards the IC pattern.
Fig. 2-3
Braided Shield Wire
Soldering Iron
IC
Fig. 2-2
IC pattern
Fig. 2-4
B2-1
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