Xoceco PH-50HA31 Schematic

PDP TELEVISION

PH-50HA31

CONTENTS

Safety precautions………………………………………………………………………..…

Alignment instructions …………………………….…….…………………………………

Method of software upgrading……………….…….……………………………………….…….

Working principle analysis of the unit……………………………….………….………….

Block diagram…………………………………..………………………………….…………

IC block diagram………………………………………………………………………..……

Wiring diagram …………………………………………………………………………….

Troubleshooting guide ………………………………………………………………..……

Schematic diagram…………………………………………………………………………

APPENDIX-A: Assembly list

APPENDIX-B: Exploded View

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3

8

10

11

12

19

20
25

Attention: This service manual is only for service personnel to take reference with. Before

servicing please read the following points carefully.

Safety precautions

Please read the “Points for attention for the Maintenance & Repair of PDP” and “Criterion for
Identifying the Defects on Screen” as below, before inspecting and adjusting the TV set.

1. “Points for attention for the Maintenance & Repair of PDP”

To avoid possible danger, damage or jeopardy to health and to prevent PDP screen from new
damage, the maintenance people must read the following carefully. If they ignore the following
warnings, there will be deathful risks:

1.1 Screens vary from one model to another and therefore not interchangeable. Be sure to use the
same type of screen in the replacement.

1.2 The operation voltage is approximately 350v for PDP module (including screen, driving circuit,
logic circuit and power module). If you want to conduct maintenance work on PDP module when the
set is in normal operation or just after the power is off, you must take proper measures to avoid
electric shock and never have direct contact or touch with the circuitry of the working module or
metal parts. That’s because within a short time relatively high voltage still remains on the capacitor
of the driving part even after the power is off. Make sure to begin relevant maintenance operation at
least one minute after the power is off.

1.3 Don’t apply on the module any power supply that is higher than the specification. If the power
supply used deviates from the value given in the specification, there might be a possibility of leading
to fire or damage to the module.

1.4 Never have operation or mounting work under unsuitable environment such as areas in the
vicinity of water (bath room, laundry, water chute of kitchen), sources of fire, heat-radiation parts or
direct exposure to sunlight. Otherwise there will be kickbacks.

1.5 In case foreign substances such as water, liquid, metal slices or others fall into the module
carelessly power must be cut off immediately. Keep the module as it is and do not move anything on
the module. Otherwise it might be possible to contact the high voltage or cause shock short circuit
so that it may lead to fire or electric shock.

1.6 If there is smoke, abnormal smell or sound from the module, please cut the power off
immediately. Likewise in case the screen doesn’t work when the power is on or during the operation,
please also cut off the power at once. No more operation in this case.

1.7 Do not remove or plug its connection wire when the module is in operation or right after the
power is off. That’s because there remains a relatively high voltage on the capacitor of the driving
circuit. If there is a need to remove or plug in the connection wire, please wait at least one minute
after the power is off.

1.8 Considering the module has a glass faceplate, please avoid extrusion by external force lest it
should cause glass breakage that may get people injured. Two people are needed in cooperation to
move this module lest contingency takes place.

1.9 The complete TV set is designed on the basis of full consideration of thermal dissipation by
convection, with the round hole on the top for heat emission. To avoid overheat, please do not have
any covering on the hole during normal operation and never put it in the place where the space is

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narrow and in bad ventilation.

1.10 There are quite a number of circuits in PDP that are integrated ones. Please be on guard
against static electricity. During maintenance operation be sure to cover yourself with anti-static bag
and before operation make sure to have it sufficiently grounded.

1.11 There are a big number of connection wires distributed around the screen. Please take care
not to touch or scuff them during maintenance or removing the screen, because once they are
damaged the screen will fail to work and it’s not possible to repair it.

If the connection wires, connectors or components fixed by the thermotropic glue need to disengage

when service, please soak the thermotropic glue into the alcohol and then pull them out in case of

damage.

1.12 Connector for the circuit board of the screen part is relatively fine and delicate. Please take
care in the replacement operation lest it should get damaged.

1.13 Special care must be taken during transportation and handling because strenuous vibration
could lead to screen glass breakage or damage on the driving circuitry. Be sure to use a strong
outer case to pack it up before transportation or handling.

1.14 Please put it for storage in an environment in which the conditions are under control so as to
prevent the temperature and humidity from exceeding the scope stipulated in the specification. For
prolonged storage please cover it with anti-moisture bag and have them piled and stored in one
place. The environmental conditions are tabulated as below:

Temperature Scope for operation 0~50centigrade

Scope for storage -15~60centigrade

Humidity Scope for operation 20%~80%

Scope for storage 20%~80%

1.15 If a fixed picture is displayed for a long time, difference in its brightness and color may occur
compared with movable pictures. But it doesn’t show any problem and the reason is that there is
reduced density of fluorescent powder in the former. On the other hand, even if changes take place
in the picture, it can keep its brightness for a period of time (several minutes). It’s a feature inherent
with plasma and it’s not abnormal. However please try as much as possible to avoid showing a still
picture of high brightness for a long time during operation.

1.16 As a digitalized display devise, this module is provided with error diffusion technology and the
gray scale and false enhancement of contour can be displayed by reusing of sub-field. As compared
with cathode ray tube, it can be found in the moving picture that at the brim of the face of a person
there are some wrong colors.

1.17 During the display of graph (indicating the gradual change in brightness horizontally or
vertically) resulting from gray scale test it can be found that the brightness for the two adjacent
levels is uneven. This is caused by the reuse of sub-field, the display of load rectification and the
electrolysis.

1.18 The screen front plate is of glass. Please make sure that the screen has been put in place
during erection. If it is not in place before the erection begins it may lead to screen crack or
breakage.

1.19 Make sure the screw used in the mounting of the screen is of the original specs lest it should
cause damage to the screen due to mismatch. Special care should be taken not to use too long or

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too big screw.

h

1.20 Care must be taken to guard against dust during assembling or dismantling, especially to avoid
dirt from falling in between the screen and the glass lest it should harm the receiving and viewing
effect.

1.21 There is piece of insulator stuck on the rear chassis corresponding to the power supply board.
It is used to isolate the cool part from the hot part. Please take care to keep it intact lest it should
become a potential safety trouble.

1.22 In addition to plasma screen, the glass is a part of high value. It has such functions as
anti-radiation, adjustment of color temperature etc. Please handle it carefully.

Alignment instructions

1. Test equipment

PM5515 (video signal generator)
MK8258 (YUV, VGA signal generator)

CA210 (white balancer)

2. The alignment flow chart (see below figure)

Connect with central signal source, then check each function of TV such as

station missing, analog control etc., check the output of headphone and speaker

Input AV/SVIDEO signal, then check each function of all the terminals

Input HD signal (format), then check each function of the terminal

Input VGA, HDMI signal, check if the display is normal, check eac

function such as analog control etc., check horizontal /vertical center etc.

Check the accessories and pack them in box

Check DDC and FLASH

To produce signal board on the line

All testing

Auto correction

Preset ex-factory

3

Fig-1 adjustment flow-chart

3. Description of adjustment

3.1 Unit adjustment

Connect the signal processing board, side AV board, button board and remote control receiver
board according to the wiring diagram. Connect with power and observe the display.

Method for using factory menu: press ”INPUT” button, then press”2580” to enter level one factory
menu. Press ”CH+” and “CH-“ to select adjustment page, then press “OK” to access. Press “CH+”
and “CH-“ to move cursor up and down, when the cursor stays on a certain adjustment item, press
“VOL-“ and “VOL+” to adjust. Press “MENU” exit to the level one factory menu; press “EXIT” to exit
from the factory menu at any situation.

Note: channel switch isn’t available at adjustment menu, only after return to level one factory menu,
you can switch channel.

3.2 Auto color adjustment

3.2.1 input 16 level gray-scale signal from MK8258 to D-sub channel, enter auto color adjustment
page of factory menu (AUTO COLOR), enter TEST PATTERN and use OK button to select GREY
SCALER16, then enter START and press OK.

3.2.2 input SMPTE COLOR BAR signal from MK8258 to YPbPr channel, enter auto color
adjustment page of factory menu (AUTO COLOR), enter TEST PATTERN and use OK button to
select SMPTE COLOR BAR, then enter START and press OK. (SMPTE COLOR BAR signal of
MK8258 should be OIRE standard, that’s ATTER 96. TYPE CODE of PATTEREDID 6.)

Note: after auto color adjustment, it must press the power button on the remote controller to turn off
the unit and then turn on, can the information be stored in FLASH!

4 Performance check

4.1 TV function

Connect RF-TV terminal to the central signal source, enter the setup menu→ auto search, check if
there is station skipping, the output of earphone and speaker, the picture are normal. The signal
should include NTSC and ATSC.

4.2 AV/S-VIDEO terminal

Input AV/S signal, check if the picture and sound are normal.

4.3 YPbPr/YCbCr terminal

Input YUV signal (VG-849 signal generator), separate input YUV format signal of table 1 and check
if the picture and sound are normal.

Table 1 YUV signal format

No H-frequency (KHz) V-frequency (KHz) Signal

1 15.734 59.94 SDTV 480i

2 31.469 59.94 HDTV 480p

3 44.955 59.94 HDTV 720p

4 33.716 59.94 HDTV 1080i

4.4 VGA terminal

Input VGA signal (VG-849 signal generator), separate input VGA format signal of table 2 and check
if the picture and sound are normal. If the image is deflection of the H-field, select manual correction
of Advanced Video Menu.

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4.5 HDMI terminal

HDMI signal format receives the three high-definition signals: 480I, 480P, 720P/60Hz, 1080I/60Hz,
except for the table 2 signal. Check if the image (contain HDCP ON and OFF) and sound are
normal.

Table 2 VGA signal format

No Resolution H-frequency(kHz) V-frenquency(Hz)

1 720 X 400 31.469 70.086 28.322 IBM

2 640 X 480 31.469 59.94 25.175 IBM

3 640 X 480 37.861 72.809 31.5 VESA

4 640 X 480 37.5 75 31.5 VESA

5 640 X 480 43.269 85.008 36 VESA

6 800 X 600 35.156 56.25 36 VESA

7 800 X 600 37.879 60.317 40 VESA

8 800 X 600 48.077 72.188 50 VESA

9 800 X 600 46.875 75 49.5 VESA

10 800 X 600 53.674 85.061 56.25 VESA

11 1024 X 768 48.363 60.004 65 VESA

12 1024 X 768 56.476 70.069 75 VESA

13 1024 X 768 60.023 75.029 78.75 VESA

Point clock pulse

frenquency(MHz)

Remark

4.6 YPBPR and TV brightness check (use 100IRE white window signal)

5 Ex-factory setting of user menu

1) Select TV channel, volume: 25

2) Video menu, Picture Mode: Nature, Aspect Ratio: Wide

3) Video menu, Advanced Video Menu:
Noise Reduction——Spatial: On
Noise Reduction——Speckle: Off
Noise Reduction——Temporal: On
Sharpness: 0

Tine: 50
Color Temperature: Cool
3D Y/C: On

4) Audio menu, Sound Mode: News, Balance: 31, Earphone Vo1:31
Digital Audio Output: AC-3, MTS: Mono

5) Setup menu, Tuning Band: Air

6) Feature menu, Sleep Timer: Off, Menu Language: English
Note: Except for Color Temperature of Cool, the Advanced Video Menu of YPBPR/YCBCR and
VGA channels sets according to the adjustment of factory.

Trouble shooting

Before servicing please check to find the possible causes of the troubles according to the table
below.

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1.Antenna(signal):

Picture is out of focus or jumping  Bad status in signal receiving

 Poor signal
 Check if there are failures with the electrical connector or

the antenna.

 Check if the antenna is properly connected.

Fringe in picture  Check if the antenna is correctly oriented.

 Maybe there is electric wave reflected from hilltop or

building.

Picture is interfered by stripe
shaped bright spots

There appear streaks or light color
on the screen

 Possibly due to interference from automobile, train, high

voltage transmission line, neon lamp etc.

 Maybe there is interference between antenna and power

supply line. Please try to separate them in a longer
distance.

 Maybe the shielded-layer of signal wire is not connected

properly to the connector.

 Check if interfered by other equipment and if interfered

possibly by the equipment like transmitting antenna, non
professional radio station and cellular phone.

2.TV set:

Symptoms Possible cause

Unable to switch the power on  Check to see if the power plug has been inserted

properly into the socket.

No picture and sound  Check to see if the power supply of liquid crystal TV has

been switched on. ( as can be indicated by the red LED
at the front of the TV set)

 See if it’s receiving the signal that is transmitted from

other source than the station

 Check if it’s connected to the wrong terminal or if the

input mode is correct.

 Check if the signal cable connection between video

frequency source and the liquid crystal TV set is correct.

Deterioration of color phase or
color tone

Screen position or size is not

proper

Picture is twisted and deformed  Check to see if the picture-frame ratio is properly set up.

Picture color changed or colorless  Check the “Component” or “RGB” settings of the liquid

Picture too bright and there is
distortion in the brightest area

 Check if all the picture setups have been corrected.

 Check is the screen position and size is correctly set up.

crystal TV set and make proper adjustment according to
the signal types.

 Check if the contrast setting is too high.
 Possibly the output quality of DVD broadcaster is set too

high.

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Symptoms Possible cause

 It maybe also due to improper terminal connection of the

video frequency signal in a certain position of the
system.

Picture is whitish or too bright in
the darkest area of the picture

No picture or signal produced from
the displayer if “XXX in search”
appears.

There appears an indication ­“outside the receivable scope)

Remote control cannot work
properly

No picture and sound, but only

hash.

Blur picture  Check if the antenna cable is correctly connected.

No sound  Check if the “mute” audio frequency setting is selected.

When playing VHS picture search
tape, there are lines at the top or
bottom of the picture.

 Check if the setting for the brightness is too high
 Possibly the brightness grade of DVD player

(broadcaster) is set too high.

 Check if the cable is disconnected.
 Check if it’s connected to the proper terminal or if the

input mode is correct.

 Check if the TV set can receive input signal. The signal is

not correctly identified and VGA format is beyond the
specified scope.

 Check if the batteries are installed in the reverse order.
 Check if the battery is effective.
 Check the distance or angle from the monitor.
 Check if there is any obstruct between the remote control

and the TV set.

 Check if the remote control signal- receiving window is

exposed to strong fluorescence.

 Check if the antenna cable is correctly connected, or if it

has received the video signal correctly.

 Of if it has received the right video signal.

 Check if the sound volume is set to minimum.
 Make sure the earphone is not connected.
 Check if the cable connection is loose.

 When being played or in pause VHS picture search tape

sometimes can’t provide stable picture, which may lead
to incorrect display of the liquid crystal TV, In this case
please press “auto” key on the remote control so as to
enable the liquid crystal TV set to recheck the signal and
then to display correct picture signal

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Method of software upgrading

1. Connect computer serial port and TV parallel port with serial wire 665.D0002-645.

2. Open iDev.exe

3. Click

Set Serial Port to the current COM port, set the Baud Rate to 1152000, Image Path to the path of the

new software. If the new software renews Bootcode, pitch on “Update boot sector” option and then click

OK.

, enter the setting interface.

4. Click

to enter the interface below:

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5. Turn on the TV, the software begins to be written.

6. After the software written, Press the power key (local keypad) and holding for several second to

force power off TV set,

7. Turn on the TV again and enter the factory menu initialization setting.

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Working principle analysis of the unit

1. NTSC signal flow:
Antenna reception NTSC signal send to the integrative tuner TDQDU4-508A, which contains HF
and IF amplifier circuit and video decoding circuit. It is controlled by main IC ZR39760 (integrate
CPU) through I2C bus. The NTSC signal via frequency tuning, HF amplification, IF amplification,
system switching and decoding, output video signal TV-CVBS of 1Vpp and sound IF signal (SIF).
TV-CVBS, AV1-CVBS, AV2-CVBS input from AV terminal and S-VIDEO via switch IC N52797EP to
output signal, one way send to ZR39760 for VEDIO DECODER, DEINTERLACE and SCALER,
then send to LVDS level drive for PDP screen, another way is output through AV output socket as
AV OUT.
The sound IF (SIF) is fed into demodulation IC ZR39760, via decoding and A/D conversion, it is fed
into ZR39760 for analog control in the format of I2S. ZR39760 outputs audio data of I2S format, it is
fed into audio D/A converter IC CS4344, output analog L/R signal. The L/R signal and sound signal
of PC/YPRPB via diverter switch HEF4052BT, send to R2S15903SP (sound processing and volume
control). Select right/left sound channel, their send to class D sound amplifier R2S15102 amplify,
then send to speaker.

2. ATSC signal flow:
Antenna reception ATSC signal send to tuner TDQU4-508A, after frequency tuning, HF
amplification, IF amplification and SAW FILTER, fed to ZR39760 for information source decoding in
the format of standard serial TS stream.
HD video signal via decoding to A/D conversion and OSD superposition, at last send to LVDS drive
level for PDP panel.
HD audio signal, via decoder built-in ZR39760, resumed to multi- channel sound of Dolby AC-3, at
the same time output data stream of I2S format and S/PDIF data stream. Audio data of I2S format is
fed to audio D/A converter chip CS4344 to output analog L/R signal. S/PDIF data stream directly
output from optical fiber interface.

3. PC/YPrPb signal flow
PC and two YPBPR signal via matched resistance, it a-c couple to video switch SN74CBT3257CDR,
via switching to selected signal to Triple Video A/D Converter MST9883 A/D conversion. Send
B/G/B of 24 bit to main IC ZR39760 digital decode, image scale and OSD superposition, then send
to LVDS level drive for PDP screen.
Sound signal (PC, YPrPb) via switch diverter HEF4052BT to output signal, it send to R2S15903SP
(sound processing and volume control) switch of audio. Select right/left sound channel, their send to
class D sound amplifier R2S15102 amplify, then send to speaker.

4. HDMI signal flow
HDMI video signal is directly fed to main IC ZR39760 (with HDCP function of HDMI) digital decode,
image scale and OSD superposition, then output LVDS drive level for screen.
HDMI audio signal via decoder built-in ZR39760, output data stream of I2S format and S/PDIF data
stream at the same time. Audio data of I2S format is fed to audio D/A converter chip CS4344 to
output analog L/R signal. S/PDIF data stream directly output from optical fiber interface.

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Block diagram

with

switch

earphone socket

KEY

PLC915

IR

PANEL

PC AUDIO

AV2

R2S15102

CD4052

R2S15903

I2S

CS5340

I2S

CS4345

ATSC DIFATSC DIF

NTSC CVBS

I2C

C

I2C

PW2300

CAT99

LVDS

ZR39760

83

SPI 32M Flash

SDRAM

DDR 256M

AV1

YPbPr Audio2

YPbPr Audio1

M52797SP

AV Audio Out

AV Out

ATSC/NTSC TNUER

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Y

S Video

P15V

330

P15V

YPBPR1

YPBPR2

330

PC

FSHDMI04+PI5V330

MAX3232C

RS232

HDMI1

HDMI2