Zenith H13A02, MX474C Schematic

SERVICE MANUAL

Model Series:

Product Type: Color TV
Chassis: MX474C
Manual Series: CM153

Manual Part #: 923-03459

Model Line: D
Product Year: 2001

General Information ....................................... 1

Servicing ..................................................... 2

Parts ........................................................... 3

Exploded views ............................................. 4

Schematics ................................................... 5

H13A02D
H13A02X

CONTENTS

Printed in U.S.A.
CN DG 5k

Published by Technical Publications

Zenith Electronics Corporation

201 James Record Road - Huntsville, Alabama 35824-1513

Copyright  October 2001 by Zenith Electronics Corporation

PRODUCT SAFETY SERVICING GUIDELINES FOR AUDIO-VIDEO PRODUCTS

A

IMPORTANT SAFETY NOTICE

This manual was prepared for use only by properly trained audio-visual 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 hazard.
These components are indicated by the letter “x” included in their component
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
modifications 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
triangle is intended to alert the service personnel to the presence
of noninsulated “dangerous voltage” that may be of sufficient
magnitude to constitute a risk of electric shock.

The pictorial representation of a fuse and its rating within an
equilateral 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 from AC line shock.
After the original service problem has been corrected, make a check of the
following:

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 trans­ported 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
particles.

4. Check for physical evidence of damage or deterioration to parts and compo­nents, for frayed leads or damaged insulation (including the AC cord), and
replace if necessary.

5. No lead or component should touch a receiving tube or a resistor rated at
1 watt or more. Lead tension around protruding metal surfaces must be
avoided.

6. After re-assembly 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 TRANSFORMER DURING THIS
TEST. Use an AC 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 metallic 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 constitutes a potential shock hazard and
must be corrected immediately.

.C. Voltmeter

Good Earth Ground
such as the Water
Pipe, Conduit, etc.

0.16uF

1600 OHM

10 WATT

Place this probe
on each exposed
metal part.

X-RADIATION

1. Be sure procedures and instructions to all service personnel cover the
subject of x-radiation. The only potential source of x-rays in current TV
receivers is the picture tube. However, this tube does not emit x-rays when
the HV is at the factory-specified level. The proper value is given in the
applicable schematic. Operation at higher voltages may cause a failure of
the picture tube or high-voltage supply and, under certain circumstances
may produce radiation in excess of desirable levels.

2. Only factory-specified CRT anode connectors must be used.

3. It is essential that the service personnel have available an accurate and
reliable high-voltage meter.

4. When the high-voltage circuitry is operating properly, there is no possibility
of an x-radiation problem. Every time a color chassis is serviced, the
brightness should be run up and down while monitoring the high voltage
with a meter, to be certain that the high voltage does not exceed the
specified value and that it is regulating correctly.

5. When troubleshooting and making test measurements in a product with a
problem of excessively high voltage, avoid being unnecessarily close to
the picture tube and the high voltage power supply. Do not operate the
product longer than necessary to locate the cause of excessive voltage.

6. Refer to HV, B+, and shutdown adjustment procedures described in the
appropriate schematics and diagrams (where used).

IMPLOSION

1. All direct view picture tubes are equipped with an integral implosion
protection system; take care to avoid damage during installation.

2. Use only the recommended factory replacement tubes.

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
tilted 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
casters across thresholds or deep pile carpets.

7. Caution customers against using a cart or stand that has not been listed
by Underwriters Laboratories, Inc. for use with its specific model of
television receiver or generically approved for use with TVs of the same or
larger screen size.

8. Caution customers against using extension cords. Explain that a forest of
extensions, sprouting from a single outlet, can lead to disastrous
consequences to home and family.

i

TABLE OF CONTENTS

SECTION 1 GENERAL INFO / REMOTE CONTROL

SPECIFICATIONS .......................................................... 1-1

SECTION 2 SERVICING

DISASSEMBLY INSTRUCTION .......................................... 2-1

SERVICE MODE LIST ..................................................... 2-3

ALIGNMENT INSTRUCTION ............................................. 2-4

ELECTRICAL ADJUSTMENT ............................................. 2-4

MAJOR COMPONENTS LOCATION GUIDE ........................... 2-7

SECTION 3 EXPLODED VIEW

EXPLODED VIEW .......................................................... 3-1

SECTION 4 PARTS LIST

COMPONENT PARTS LIST ............................................... 4-1

SECTION 5 SCHEMATIC

H13A02D/02X POWER SUPPLY CIRCUIT ........................... 5-1

H13A02D/02X DEFLECTION CIRCUIT ............................... 5-2

H13A02D/02X MAIN MICRO & TUNER CIRCUIT .................. 5-3

H13A02D/02X CHROMA CIRCUIT .................................... 5-4

H13A02D/02X AUDIO CIRCUIT ....................................... 5-5

H13A02D/02X PCB LAYOUT TOP ..................................... 5-6

H13A02D/02X PCB LAYOUT BOTTOM ............................... 5-7

CM153 TOC MX474C - TOC

SPECIFICATIONS

MODEL

ITEMS

TV STANDARD NTSC-M
POWER INPUT AC 120V 60 Hz
POWER CONSUMPTION
TUNING SYSTEM Frequency Synthesizer ( FS ) Tuning System

TUNING RANGES

SOUND OUTPUT
SPEAKER
ANTENNA INPUT IMPEDANCE 75 ohm Unbalanced

AUXILIARY

INPUT TERMINAL

INTERMEDIATE
FREQUENCIES

Picture IF Carrier Frequency : 45.75 MHz

H13A02D / H13A02X

54W

VHF : 2 ~ 13 (12)

~

~

1.0 W

Front :

Rear:

69 (56)

181 (181)

UHF : 14

CATV : 1

1 W 8 ohm

Ear Phone Jack

VHF/UHF Antenna Input

Sound IF Carrier Frequency : 41.25 MHz

REMARKS

REMARKS

CM153 1-1 MX474C - GENERAL INFO

SERVICE MODE LIST

This unit provided with the following SERVICE MODES so you can repair, examine and adjust easily.
To enter the Service Mode, press both set key and remote control key for more than 1 second.

Set Key Remocon Key Operations

VOL. (-) MIN

VOL. (-) MIN 1

VOL. (-) MIN

VOL. (-) MIN 8

VOL. (-) MIN 9

0

6

Releasing of V-CHIP PASSWORD.

Initialization of the factory.
NOTE: Do not use this for the normal servicing.

POWER ON total hours is displayed on the screen.
Refer to the "CONFIRMATION OF USING HOURS".

Can be checked of the INITIAL DATA of MEMORY IC.
Refer to the "NOTE FOR THE REPLACING OF MEMORY IC".

Writing of EEPROM initial data.
NOTE: Do not use this for the normal servicing.

Display of the Adjustment MENU on the screen.
Refer to the "ELECTRICAL ADJUSTMENT" (On-Screen Display Adjustment).

CONFIRMATION OF USING HOURS

POWER ON total hours can be checked on the screen. Total hours are displayed in 16 system of notation.

1.

Set the VOLUME to minimum.

2.

Press both VOL. DOWN button on the set and Channel
button (6) on the remote control for more than 1 second.

3.

After the confirmation of using hours, turn off the power.

ADDRESS DATA

INIT 00 83
CRT ON

0010

FIG. 1

Initial setting content of MEMORY IC.
POWER ON total hours.

= (16 x 16 x 16 x thousands digit value)
+ (16 x 16 x hundreds digit value)
+ (16 x tens digit value)
+ (ones digit value)

NOTE FOR THE REPLACING OF MEMORY IC

If a service repair is undertaken where it has been required to change the MEMORY IC, the following steps should be taken to
ensure correct data settings while making reference to TABLE 1.

Table 1

09

INI
0A

FF

ADDRESS

DATA

1.

Enter DATA SET mode by setting VOLUME to minimum.

2.

Press both VOL. DOWN button on the set and Channel button (6) on the remote control for more than 1 second.
ADDRESS and DATA should appear as FIG 1.

3.

ADDRESS is now selected and should "blink". Using the SET + or - keys on the remote, step through the ADDRESS until
required ADDRESS to be changed is reached.

4.

Press ENTER to select DATA. When DATA is selected, it will "blink".

5.

Again, step through the DATA using SET + or - until required DATA value has been selected.

6.

Pressing ENTER will take you back to ADDRESS for further selection if necessary.

7.

Repeat steps 3 to 6 until all data has been checked.

8.

When satisfied correct DATA has been entered, turn POWER off (return to STANDBY MODE) to finish DATA input.

The unit will now have the correct DATA for the new MEMORY IC.

CM153 2-1 MX474C - SERVICING

INI00INI01INI02INI03INI04INI05INI06INI07INI08INI

0809A00106B324992125

ALIGNMENT INSTRUCTIONS

1. SERVICE MODE ADJUSTMENS

Follow the steps below whenever service adjustment is required. See Table- A and Table- B to determine if
service adjustments are required.

NOTE

\

To perform the service mode for model H13A02D/02X, please perform the following steps on part OS101.

1) Remote control PN# 924-10053 is needed to complete the following.

2) Remove 3pin terminal at location OS101 and add IR sensor PN# 942-10065.

3) Enter the Service mode and adjust.

4) Remove IR pre Amp after all menu adjustments have been completed.

1) How to enter the service mode using your remote control.

•

Turn the set on.

•

Direct the remote control to the reception window of TV.

•

Push buttons of remote control in sequence as follows.

Menu (5 sec.)

•

Then, the screen will appear as follows.

9

8

7

6

S2 SCRN
S5 IFC
S6 GEO
S8 W/B
S9 DP
S12 FACT
S10 SOUND
REM Zenith

NOTE

If you changed the setting of “REM Zenith” item, then your remote control will not work. In that case, unplug your
power cord and plug it again.

•

Using the channel up or channel down button, select the item you wish to adjust.

(The color of selected item turns

•

Press the volume up or down button to enter in the service mode you wish to adjust.

red.)

CM153 2-2 MX474C - SERVICING

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

Fig. 1-4

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.

Fig. 1-5

CM153 2-3 MX474C - SERVICING