Akira 21WHP3-BN Schematic

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Model No: 21WHP3-Bn
Version 1.0

3

CONTENTS

SAFETY NOTICE.......................................................................................................................................4

GENERAL DESCRIPTION........................................................................................................................6

TECHNICAL SPECIFICATION................................................................................................................7

GENERAL SPECIFICATION....................................................................................................................8

SAFETY CAUTIONS FOR PRODUCTS..................................................................................................9

ADJUSTMENT MODE ............................................................................................................................10

CHASSIS BLOCK DIAGRAM ................................................................................................................15

FAULT FINDING TREES........................................................................................................................16

IC BLOCK DIAGRAM.............................................................................................................................23

MAIN CHIP INSTRUCTION...................................................................................................................24

FACTORY MENU

EXPLODED VIEW AND PART NAME.................................................................................................48

BOM LIST .................................................................................................................................................49

CIRCUIT DIAGRAM ...............................................................................................................................58

Model No: 21WHP3-Bn
Version 1.0

....................................................................................................................................45

4

SAFETY NOTICE

WARNING: BEFORE EXAMINING AND
SERVICING THIS CHASSIS, READ
CAREFULLY THE FOLLOWING
SAFETY INSTRUCTIONS.

X-RAY RADIATION PRECAUTION

1. The primary source of X-RADIATION in television receiver is the picture tube. The picture

tube is specially constructed to limit X-RADIATION emissions. For continued X-RADIATION

protection, the replacement tube must be the same type as the original including suffix letter.

Excessive high voltage may produce potentially hazardous X-RADIATION. To avoid such

hazards, the high voltage must be maintained within specified limit. Refer to this service manual,

high voltage adjustment for specific high voltage limit. If high voltage exceeds specified limits,

take necessary corrective action. Carefully follow the instructions for +B1 volt power supply

adjustment, and high voltage check to maintain the high voltage within the specified limits.

2. The EHT must be checked every time the receiver is serviced to ensure that the CRT does not

emit X-ray radiation as result of excessive EHT voltage. The nominal EHT for this receiver is

22KV at zero beam current (minimum brightness) operating at AC 220V. The maximum EHT

voltage permissible in any operating circumstances must not exceed 25KV. When checking the

EHT, use the High Voltage Check procedure in this manual using an accurate EHT voltmeter.

3. The only source of X-RAY radiation in this receiver is the CRT. To prevent X-ray radiation,

you should use the same type of CRT when replacing it.

4. Some components used in this receiver have safety-related characteristics preventing the CRT

from emitting X-ray radiation. For continued safety, replacement component should only be made

after referring the Product Safety notice below.

SAFETY PRECAUTION

1. The high voltage in the TV reaches to 22KV when the TV is in operation. Be more careful

during opening the back cover.

a. The high voltage existing in the TV is very dangerous. Refer servicing to qualified

personnel only.

b. Before removing the high voltage cap. Discharge the anode of the CRT and the

chassis in case of electric shock.

c. Wear a pair of goggles when handling the CRT to avoid broken pieces damaging

your eyes.

d. Do not hold the CRT neck in case of causing damage to the CRT.

2. When the power cord needs replacing, use the same one as that provided by AKIRA factory.

3. Voltage exists between the hot and cold ground when TV is in operation. Install a separation

transformer during repairing or connecting to any tester for the sake of safety. The power of

the separation transformer should be beyond rated overall power.

Model No: 21WHP3-Bn
Version 1.0

5

4. When replacing a burnout fuse, use the one with the same specifications as the original.

5. When replacing old wire, wind new one round the shaft to weld. When replacing components

with safety in performance, use the same type as that specified by AKIRA and install it in the

former way.

6. Never place wire near high-temperature or high-voltage components.

7. An isolation transformer should be connected in the power line between the receiver and the

AC line when a service is performed on the primary of the converter transformer of the set.

8. Comply with all caution and safety-related notes provided on the cabinet back, inside the

cabinet, on the chassis or the picture tube.

9. When replacing a chassis in the cabinet, always be certain that all the protective devices are

installed properly, such as, control knobs, adjustment covers or shields, barriers, isolation

resistor-capacitor networks etc.. Before returning any television to the customer, the service

technician must be sure that it is completely safe to operate without danger of electrical shock.

PRODUCT SAFETY NOTICE

Product safety should be considered when a component replacement is made in any area of a receiver.

Components indicated by mark in the parts list and the schematic diagram designate components in

which safety can be of special significance. It is particularly recommended that only parts designated

on the parts list in this manual be used for component replacement designated by mark. No deviations

from resistance wattage or voltage ratings may be made for replacement items designated by mark.

Model No: 21WHP3-Bn
Version 1.0

6

GENERAL DESCRIPTION

AKPH02 chassis series are applied in A14P01/A21P01 respectively which uses
mainly Philips’ advanced UOC-ultimate chip TDA935X/6X/8X and I2C-bus
controlled IC. With combination of microcontroller and small signal processor, the
TDA935X/6X/8X series feature high-integration, high-performance-to-price ratio and
high-reliability and advanced functions with fewer external components, which
provide much convenience for manufacturing and technical service.

Table 1 provides A14P01/A21P01 mainly ICs and functions.

THE SURVEY

Table 1, the main IC and functions

Position Type Function Description
N301 TDA9361/TDA9381 Microcontroller and small signal

processor(UOC)
N702 ST24C08-W EEPROM
N701 AN7522N Sound power amplifier
N401 LA78040 Vertical scan output stage circuit
N801 LC4052B/CD4052BE AV1/AV2 Switch
N121 LC4052B/CD4052BE AV1/AV2 Switch

SIGNAL PROCESS

The TV signal enters into tuner (A201) from cable or antenna. Pin 10 and pin 11 of N301 are combined
to select the band. Pin 4 of N301 outputs PWM tuning signal. The 38.9MHz IF signal is coupled to
V308 (pre-amplify) and then to SAWF (Z301). After processed in the SAWF, the 38.9MHz signal gets
to pin 23 and pin 24 of OM8370. The IF circuit in OM8370 includes such unit as the AGC amplifying
circuit, 38.9MHz oscillator, PLL video demodulator, video amplifier, IF identify circuit and AFT
circuit. The demodulated signal (CVBS) comes from the pin 38 of OM8370, the sound signal comes
from the pin 44.

The internal CVBS signal needs norm identification then outputs from pin 38 of OM8370, via the trap
circuit (composed of the V351, Z351, Z354, V352 and so on) feeds back to the pin 40 of OM8370. The
RGB signal comes from pin51, Pin52, Pin53 of OM8370, and outputs to the CRT board. The internal
sound signal comes from pin 44 of OM8370 and then input to pin 1 and pin 12 of HEF4052BP. The
sound signals from RF and AV are selected in it. The selected signal is output from Pin 3 and pin13,
then input AN7522N (sound amplifier) or output from AV terminals.

Model No: 21WHP3-Bn
Version 1.0

7

TECHNICAL SPECIFICATION

Test Item Conditional TD171

AC Operating
Range

Total Power
Consumption

EHT

Anode Current Brightness &contrast Maximum I

Heater Voltage TV operate normally V

B+ Normal operating VB+ = 112Vdc
Sound power

output

RF&AV signal input with sound loud speaker
(volume maximum) & Picture set in Dynamic
mode

Philips or Mono-scope pattern signal with howling
sound Contrast & Brightness set in Maximum,
sound increase maximum

Standby Mode 14 Watts

Brightness & contrast set in Maximum Min: 26.2KVdc

Typical Design value Average: 26.5KVdc

Brightness &contrast Minimum Max: 27.8KVdc

RF signal input broadcasting at

217.25MHz/BG/DK(1KHz)
Volume is maximum

140Vac ~ 240Vac

90Watts

≤ 1.2mA

ABL

= 6.2Vac

Heater

V = 6.3Vrms
P = 5Watts X 2

Model No: 21WHP3-Bn
Version 1.0

8

GENERAL SPECIFICATION

Power consumption

Receive system DK/BG/I
Color system PAL/ SECAM/ NTSC
Vision intermediate
frequency

Inter-carrier frequency

Chroma if frequency PAL 34.47/ 35.32MHz
Antenna type DIN TYPE 75 Ohm

Channel receiving

Tuning system VS tuning
AV IN/ OUT 2 AV STEREO IN + 1 AV STEREO OUT
Component IN 1 YUV-Component IN

AV IN/ OUT specification

OSD language

Audio output power > 8W (1KHz, 0.5V INPUT, 10% THD
Safety authentication
standard
LED indicator Power ON
Hand set type HS08
Hans set power supply Pin AAx2
Color picture tube 14” 21” 90 degree tube
Remote control distance 5m

External input/output

2

 I

C Bus Control

 Auto Search
 Off/On Timer
 Teletext

14” 70W MAX
21” 90W MAX

38.9MHz

5.5 MHz(B/G)

6.5MHz(D/K)

VHF Low channel
(VL)
VHF high channel
(VH)
UHF channel (U) =471.25 to 863.25 MHz

VIDEO IN ----1.0 0.2V
AUDIO IN ----0-2V (RMS)
VIDEO OUT ----1.0 0.2V
AUDIO OUT ---- 0-2V (RMS)
English, Russian, Turkish, French, Spanish, Vietnamese,
Indonesian, Arabian, Persian

CB

Video/Audio (L/R) 2set input
YUV input
S-Video input
Video/ Audio (L/R) 1 set output

=48.25 to 147.25 MHz

=154.25 to 463.25 MHz

75 Ohm

p-p

p-p

75 Ohm

Model No: 21WHP3-Bn
Version 1.0

9

SAFETY CAUTIONS FOR PRODUCTS

Many electric and mechanical components in AKPH01 chassis have special safety performances,

which are always neglected. Even if replacing them with some components with the same voltage and

power, you can not get effective protection to X-ray. In the circuit diagram, these special electric

components are indicated by the special mark ! and on the shadow. When replacing any of them, use

the one with the same specifications as the original’s. Otherwise, it may cause X-ray radiation and

damage to overall safety.

CIRCUIT ADJUSTMENTS

GENERAL INFORMATIONS

All adjustment are thoroughly checked and corrected when the receiver leaves the
factory. Therefore the receiver should operate normally and produce proper color and
B/W pictures upon installation. However, several minor adjustments may be required
depending on the particular location in which the receiver is operated.

This receiver is shipped completely in carton. Carefully draw out the receiver from
the carton and remove all packing materials. Power cord into a convenient 220 volts
50 Hz AC two pin power outlet. Turn the receiver ON. Check and adjust all the
customer controls such as BRIGHTNESS, CONTRAST and COLOUR Controls to
obtain natural color or B/W picture.

AUTOMATIC DEGAUSSING

A degaussing coil is mounted around the picture tube so that external degaussing after
moving the receiver is normally unnecessary, providing the receiver is properly
degaussed upon installation. The degaussing coil operates for about 1 second after the
power to the receiver is switched ON. If the set is moved or faced in a different
direction, the power switch must be switched off at least 30 minutes in order that the
automatic degaussing circuit operates properly. Should the chassis or parts of the
cabinet become magnetized to cause poor color purity, use an external-degaussing
coil. Slowly move the degaussing coil around the faceplate of the picture tube, the
side and front of the receiver and slowly withdraw the coil to a distance of about 2m
before disconnecting it from AC source. If color shading still persists, perform the
COLOUR PURITY ADJUSTMENT and CONVERGENCE ADJUSTMENTS
procedures.

Model No: 21WHP3-Bn
Version 1.0

10

ADJUSTMENT MODE

Item B+ adjustment, TV signal receiving

AKPH01 chassis

Measuring
Equipment
Preparation
Before Adj.

TV SG (Signal Generator)
Digital multi-meter
The set is turned on
Connect the TV SG to RF input terminal of the set.

Adjustment procedure

1, Turn VR501 potentiometer to adjust B+ to specified voltage.
2, Check voltages for video out, vertical out, circuit work and audio

power out as follow

+B 110 110

Video Out 188 188

Vertical Out 26 26

Voltage (volt)

14 inch 21 inch

Tolerance

±2V

±5V

±1V

Circuit Work 13 13

Audio Power Out 12 12

3, TV signal receiving

1. Press MENU key, to select POS.MEMORY item.

Press V+ or V- key, to select SEARCH or AUTOMEMORY
item, press P+ key to start searching.

2. Press P+ or P- key to inspect the set if there is channel skipped,

if so, searching again by SEARCH as above described.

Model No: 21WHP3-Bn
Version 1.0

±1V

±1V

11

Item

AKPH01 chassis

Measuring
Equipment
Preparation
before Adj.

Inspection procedure
1, Input the TV signal which system is designated in technical specification
2, Switch TV system to the set by pressing SYS key on user remote controller

according to the TV system in SG. The picture and sound must be normal.
3, Press TV/AV key, to select AV input. The picture and sound must be normal

4, AV output inspection. Load a 75Ω resistor to VIDEO output terminal,1Vp-p

video output signal that is from TV signal should be observed on the

oscilloscope. Load a 10K resistor to AUDIO output terminal, 0.7Vp-p audio

output signal that is from TV should be observed on the oscilloscope.

TV system adapting & AV in/output
inspection

SG (with NTSC3.58). User remote controller
Dual trace oscilloscope

Input TV and AV signal

Item Focus adjustment

AKPH01 chassis

Measuring
Equipment
Preparation
before Adj.

SG

Brightness, contrast and color should be set in standard

Adjustment procedure

1, Receive the cross-hatch pattern signal
2, Turn the focus adjusting VR watching the screen and adjust the vertical line of

mark to make the most thin. Then the focus adj. VR is set as close low voltage
side as possible.
Stop the focus adj. VR at the point that focus is a bit worse at once, turn back to the

left and then turn back to the right a little again.

Model No: 21WHP3-Bn
Version 1.0

12

Magnified drawing of part

Item White balance adjustment

AKPH01 chassis

To be fine

H. line

V. line

Measuring
Equipment

Preparation
before Adj.

MENU9 CRT cut-off and white balance and sub-brightness adjustment.

Receive gray and white 2 steps signal.

CRT cut off adjustment.

a)

1. push [P+][P-] key to select “SC”, push [V+][V-] key then automatically vertical
scan will be stopped.

2. adjust SCREEN control on Flyback transformer to get the darkest single

horizontal line (red,

purple or more white

3. push [V+][V-] key again, vertical scan work repeat.

white balance adjustment.

b)

a) select RD/BD menu.
b) adjustment RD/BD to get color temperature as x=282, y=292.

sub-brightness adjustment (use stair case signal)

c)

1.

adjust SB to get the darkest step being out off.

Model No: 21WHP3-Bn
Version 1.0

SG and white balance meter
service remote controller

Warm up the set for more than 30 min.
Brightness, contrast and color should be set in standard

green, or blue, sometimes shows more yellow, more

).

select SB MENU.

13

Item RF. AGC adjustment

AKPH01 chassis

Measuring
Equipment

Preparation

before Adj.
Adjustment procedure
1, Receive the color bar signal that is 87.5% modulation and 60dBu level
2, Press AGC-TOP on service remote controller to select AGC-TOP adjustment,

press + or – key to adjust the voltage of AGC-TOP to 6.2±0.05V that is read on

the digital multi meter.

Item

AKPH01 chassis

Measuring

Equipment

Preparation

before Adj.

MENU8 Geometrical adjustment

Receive standard Crosshatch pattern

signal for PAL system .

Adjust VSLOPE value, to the horizontal

a)

line just appear from

half bottom shadow.

Adjust VSHIFT value, the center

b)

horizontal line correspond to

CRT vertical center.

Adjust Vamp value, to get 90% of vertical picture contents would be displayed

c)

on CRT.

Adjust HSHIFT value, to get the picture horizontal center correspond to CRT

d)

horizontal center.

Receive standard Crosshatch pattern signal for NTSC system, and again adjust.

e)

SG and digital multi meter
service remote controller

Connect a digital multi meter to AGC point on the chassis

Vertical height, linearity and Hor. position adjustment

SG
service remote controllers

Brightness, contrast and color should be set in standard

.

Horizontal line

Shadow

Model No: 21WHP3-Bn
Version 1.0

14

Item OSD position adjustment

AKPH01 chassis

Measuring

Equipment

Preparation

before Adj.

Adjustment procedure
1, Press 5 key on service remote controller to set the set into design mode adjustment
2, Press ↑ or ↓ key to select OSD VPOS item, press → or ← key to adjust the OSD to
the center position on the screen or press OSD HPOS on service remote controller
and press + or – key to adjust the OSD position.
3, Press M key again to quit design mode adjustment.

service remote controller

Brightness, contrast and color should be set in standard

Item The functions of the set inspection

AKPH01 chassis

Measuring

Equipment

Preparation

Before Adj.

Inspection procedure
1, Receive the Philips pattern signal
2, Press PIC key on user remote controller to call the menu as adjusting picture
quality. Adjust color, brightness, contrast, sharpness and tint (in NTSC)
respectively and all adjustment should be right
3, Press V+ key to increase the sound volume, no distortion heard at maximum
level, press V- key to decrease the sound volume, no sound heard at
minimum level
4, Press POWER key to switch the set into standby status, at mean time the
manufactory adjustment mode is cancelled
5, Press POWER key again, the set should work in normal receiving mode
6, Press (mute), QV (display), PP and TIMER key respectively,
the relevant function should be normal

SG
User remote controller

The set is turned on

Model No: 21WHP3-Bn
Version 1.0

15

CHASSIS BLOCK DIAGRAM

Video-out
Audio-out L
Audio-out R
Video-in1
Audio-in1L
Audio-in1R

Y
Cr
Cb

S-video

HF TUNER

A101

BAND1

BAND2

KEY BOARD

AC150-260V

50/60Hz

V-in2 A-in2LA-in2R

14

15

N801CD4052

11

11

15

IF PRE-AMP

V308

REMOTE

RECEIVER

U701

AV SWITH

14

AV SWITH

N161CD4052

12

13

9

10

2 3 4 5

13

10

1

SAWF

Z301

MEMORY

N702

ST24C08

Resistance

disturbance

C501L502

rectification

VD503-VD506

TV AUDIO OUT

9

Bridge

SIF TRAPS

Z351,Z352,Z354

V352

6

AUDIO AMPLIFIER

12

10

SP161

8Ω5W

R

(N101) AN7522N

SP162

L

8Ω5W

63

62

44

47

46

48

43

V351

42

38 7

PHILIPS UOC

TDA9351/61/81

40

53

52

51

21

8

9

VIDEO
AMPLIFIER
V912V913
V922V923
V932V933

FIELD OUTPUT

4

2

CRT

POWER AMP

23

24

11

10

6

64

2

3

SCL

6

SDA

5

22

33

N401LA78040

HORIZONTAL

DRIVE

V450

T450

HORIZONTAL

OUTPUT

V451

HEAT

FOCUS

EHT

SCREEN

FBT(T402)

BSC25

-15V

Filter C507

+300V

POWER SUPPLY

CIRCUIT

V1512V553V1511T

501N504

16V

13V

15V

24V

110V

200V

+15V

Model No: 21WHP3-Bn
Version 1.0

16

N

FAULT FINDING TREES

A Three-None(no raster, no picture, no sound)
This failure is mainly caused by big-power circuit such as power supply, horizontal scanning, vertical scanning.
The detail checking and repairing steps are as follow.

Voltage of C507

NO

Check if V1513 collect-emitter
Was broken down

0V

Check XR502,F501,power

Swich, AC cord and plug

YES

Check V1513,V1512,F501,XR502,VD503

300V

Test voltage of V1513 base

0.6V

Check T501,VD1517,
C1515,C1517,V451,

Check if it get right
When cut off V504

VD522-VD529
C455,C456,T451
C467

Test the voltage of
N301 pin1

CPU has sent the
Power-off signal

Check the voltage
of V1513 collector

0V

YES

4.5-5.5V

300V

1V

0V

0V

Check T501

Check V1513

0V

Check if V504
is broken down

Test the voltage of C528B

50V

Cut off R458

NO

V

V

e

r

e

r

e

r

,

,

,

variation

v

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4

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2

4

V

2

4

V

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T

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h

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1

8

8

V

1

8

8

1

8

a

a

8

s

s

a

s

LOW

VD525,VD1561,VR501,V542,
VD1517,V504,V1511

Check VD522,C528B

115V

Recover R458, unplug
XS403 for a While,then
test the voltage of C528B

No variation

Check V451,T451,T450,

Deflection coil

Check L452,VD436,C461

Deflection coil

s

d

115V

s

u

s

u

d

Normal

c

h

c

h

u

c

h

1

2

V

1

2

V

1

2

V

Check V451 pin C voltage

Check T451,V451,R458

130V

115V

N301 pin39voltage

8V

N301 pin33 voltage

2V

V450 pin C voltage

24V

Check R452,V450

Others

115V

Check R539,V1553,VD1561

504,V1511,V1512,R556

Others

Check N301,N401

0V

Check VD543,C525,
]R454,C453,T450,
C455,V451

0V

Check T451

Model No: 21WHP3-Bn
Version 1.0

17

B Two-None (no picture, no sound)
The failure shows that the set does not display the picture but it has noise wave or blue background or OSD on the screen. This means that the circuits of power supply, horizontal scanning, vertical scanning

and video amplification are normal and they are not considered in the repairing. The failures are mainly in the small signal processing circuits.

Before checking these circuits, a kind of practical test method is introduced. It is called “Signal-input way ”. The detail is described as follow: We can use the resistance function of an analog multimeter,

connect the red pole (negative in ohm scope) on the circuit board ground, then touch softly the test point with another pole (black pole) in ohm scope meanwhile observe the reactivity on the output device.

Note : In the TV test, we mainly observe the noise wave on the CRT and listen to the noise voice liking as “Ka…..Ka” from the loudspeakers.

1. No picture

Check RF signal input and adaptor

Check N703, A101

Check R301,R302,
N301,A101

NO

Check if A101 has input signal

Check the “ VT ” voltage when auto searching

0V

Check the “ +5V ” voltage on A101

0V

The voltage between VL and BH vary from 0V to
5V or not when auto searching

No picture

YES

YES

Out of the “ 0-33V ” range

In the “ 0-33V ” range

5V

Check R703,N703,C703A

33V

The voltage on the C703

33V

No variation

Check the voltage on the C705

0-33V

Check R707, C707, A101

Check ,V701,N301, R701, R701A
,R704,R705,C701,C705,C706

Model No: 21WHP3-Bn
Version 1.0

18

Check R317, R318, R316,C307,A101,N301

Check,L331, C333, L752,C753A, L751, C751

Observe if there is snow-noise-wave disturbance on the CRT via using “Signal-input way ” by touching pin 23 and pin 24 of N301

YES

Observe if there is snow-noise-wave disturbance on the CRT via using “ Signal-input way ” by touching pin 38 of N301

Observe if there is snow-noise-wave disturbance on the CRT via using “Signal-input way ”by touching pin 17 of N301

Observe if snow-noise-wave disturbance on the CRT via using “ signal-input way ”by touching pin 40 of N301

Check if voltage on pin 31 of N301 is 1.7V

≥2V

Check C323,A101,N301

2V

Exam the voltage of “ AGC ” on A101 without antenna

3.8V

0V

Test the voltage on pin 14, 54, 56of N301

8V

Test the voltage on pin 51, 52, 53, 50 of N301

5V

NO

NO

NO

NO

Test if there is the sync signal on the pin 39 of N301

NO

Check C361,C362,L361,N301

Observe if these is snow-noise-wave disturbance on the CRT via using “ Signal-input way ” by touching pin 51,52,53 of N301

Check R381,R382,R383,V912,V922,V932,N301

0V

YES

Check N503, N301,C532, R565,C524,
,VD561,V542

YES

Check N505, N301

YES

Check R331,C336,C337

YES

Check V351,V352,L351,Z351,C364

NO

Model No: 21WHP3-Bn
Version 1.0