Xoceco PH-42HU31 Schematic

PDP TELEVISION

PH-42HU31

CONTENTS

Safety instructions………………………………………………………………………..…

Adjustment instruction …………………………….…….…………………………….…

working principle analysis……………………………….………….…………………….

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

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

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

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

Schematic diagram…………………………………………………………………………..

APPENDIX-A: Assembly list

APPENDIX-B: Exploded view

1

3

6

7

8

14

15

20

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 – bathroom, 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
narrow and in bad ventilation.

1

1.10 There is 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 thermosopic 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
too big screw.

1.20 Care must be taken to guard against dust during assembling or dismantling, especially to avoid

2

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

PM5518 (video signal generator)
VG-849 (VGA and HDMI signal generator)
CA210 (white balancer)

2 Alignment flow-chart

The alignment flow-chart is shown as fig-1

Check DDC, HDCP KEY, FLASH and POWER control IC

Factory initialization setup

IF channel AFT voltage of TV and AGC voltage

VGA, YPbPr ADC correction

White balance adjustment

Fig-1 adjustment flow-chart

3 Unit adjustments

Connect all the boards according to wiring diagram, connect with power and observe the display.
Method for entering factory menu: press “INPUT”, “2”, “5”, ”8” and “0” in turn to enter factory
menu; press “CH+” and “CH-” to select adjustment items and press “VOL+” and “VOL-” to adjust
value items, press “MENU” continuously to exit.
Method for software upgrading: enter factory menu and select “OPTION”, set ISP to 1 or insert
jump wire J1, then you can upgrade on line. After upgrade, set ISP back to 0 or pull out jump wire
J1.

3.1 Initialization
Enter factory menu, select “OPTION” and “HOTEL OPTION” sub-menu, adjustment of items to see

Performance check

Preset ex-factory

3

table1.

Table1 sub-menu adjustment

Items Preset Introduce

HOTEL 0 1: HOTEL OPTION of factory menu is optional

0: HOTEL OPTION of factory menu is not optional

LOGO 1 1: display LOGO in no signal or turn on

0: no LOGO display

ADC PRESCALE 00A Software auto preset according the power consumption

SIF PRESCALE 000 Software auto preset according the power consumption

BACK LIGHT 13 Software auto preset according the screen

ALL COLOR 1 1: white balance of each channel auto offset based on the HDMI white

balance

0: white balance of each channel adjust the offset base separately

NO STANDY 0 0 01: turn on 00: memory function of turn on 10: standby

INIT VOLUME 0-100 Volume when turn on

INIT CHANNEL 1-200 Channel when turn on

INIT SRC Program source Input Source when turn on

EEPROM-MEMORAY

RECALL

> EEPROM Initialization (operate when EEPROM data chaos)

3.2 Adjustment for AFT voltage and AGC voltage of IF channel in TV

3.2.1 IF AFT adjustment
Enter factory menu, set IF VCO to 1, or press ”INPUT”, “2”, “5”, “8”, “1” to enter VCO

adjustment mode, disconnect J2, adjust LZ100 to value 2.5V of TP5(B face), then wed J2.

3.2.2 IF AGC adjustment

Input 184.25MHz RF signal of 60DBuv from RF terminal for china, and 175.25MHz for
America, adjust RZ133 to value 2V of TP1(B face) and there should be no obvious snowy picture.
Increase the signal to 90DBVuv and it should be display normally and no obvious noise.

3.3 White balance adjustment

3.3.1 HDMI white balance correct

a. Input VG-848 signal to HDMI: TIMING854(800*600/60Hz) 8 level gray scale of PAT920,

adjust the balance with CA210.

b. Enter COLOR TEMP sub menu and select color temperature of standard(9300K)

c. Fixed B OFF, adjust R OFF, G OFF to let the color coordinate of the second level be
283,297(CPT panel) and the brightness be 3nit ~10nit or so; Fixed B GAIN, adjust R GAIN, G GAIN
to let the color coordinate of the seventh level be 283,297(CPT panel). Repeat adjust R OFF, G OFF,
R GAIN and G GAIN, until the two color coordinate of the level gray scale be 283,297(CPT panel).

3.3.2 VGA/YPbPr white balance check and correct

a. Connect VG-848 signal of VGA to VGA terminal and input TIMING854(800*600/60HZ)
(PATTERN:CROSS), and auto adjust to full screen then input PAT948 black/white signal, enter
submenu of ADC ADJ, select AUTOTUNE and wait for OK display. Input PAT920(8 gray levels),
check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according the
method of 3.3.2

b. connect VG-848 signal of YPbPr to YPbPr terminal and input TIMING972(1080I/60Hz)

4

PAT908 color bar(include back/white bar), enter submenu of ADC ADJ, select AUTOTUNE and wait
for OK displaly. Input PAT920(8 gray levels), check if the white balance is normal, if not, set ALL
COLOR to 0 and fine adjust according the method of 3.3.2

c. Input AV signal(PM5518, 8 gray levels PAL for China and NTSC for America) to VIDEO 1
terminal, check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according
the method of 3.3.2.
Note: it can’t set back to 1 once ALL COLOR changes to 0.

4 Performance check

4.1 TV function
Enter searching menu → auto search, connect RF-TV terminal with central signal source and check
if the picture is normal, if there are channels be skipped. Check CCD and V-CHIP function for
America.

4.2 AV/S, YPbPr terminals
Input AV/S, YPbPr/YCbCr HD signal, check if it is normal.

4.3 VGA terminal
Insert VGA terminal, input VGA format signal of 640X480@60 Hz and check if the display is normal.

4.4 HDMI terminal
Insert HDMI terminal, input 640X480@60Hz signal, check if the display is normal. Check HDCP
function.

4.5 check sound channel
Check the speaker and earphone of each channel.

4.6 RS232 terminal
Put the earphone line into COM terminal, check the long-distance control function with special test
software.

4.7 other function check
Check the turn on/turn off timer, asleep timer, picture/sound mode, OSD, freeze/mute,
stereo/SAP(for America), ect.

4.6 presetting before ex-factory

Item Setting Item Setting Item Setting

PICTURE MODE NAUTRAL OSD English/Chinese

COLOR MODE DK HALFTONE 50

SOUND MODE NEWS DURATION 15 VGA/HDMI STANDARD

NR WEAK ANTENNA CATV

ZOOM FULL Turn off channel TV

5

Working principle analysis of the unit

The RF signal received by antenna will be sent to tuner TUN1, then IF signal will be obtained
through high amplifier and mixed frequency, through pre-intermediate amplified by VZ100, then it
will be sent to acoustic surface-wave ZZ101 to do IF filter and get better IF characteristics, then it
will be sent to NZ100 (R2S1040) to do intermediate amplification, phase-locked loop VCO and
synchronous wave detection to get video signal TV-CVBS; after pre-intermediate amplification IF
will also be sent to acoustic surface-wave ZZ100 to do filter at the same time, then it will be sent to
NZ100 to do intermediate amplification and output the second sound intermediate frequency signal
(TV-SIF).

The TV-CVBS signal output from R2S1040 together with TV-SIF will be sent to main IC NS4
(MST9U88L). Video signal of AV1, AV2, S-VIDEO, YPbPr1 and YPbPr2 will also be sent to
MST9U88L; while the audio signal of them via audio switch NW200(HEF4052BT) selection to
MST9U88L (AV1 and S-VIDEO share one audio port). Video and audio signal of VGA, HDMI will be
sent to MST9U88L, too.

The main IC NS4(MST9U88L) is a high performance and fully integrated IC, which can realize
HDMI interface processing, video demodulating, video switch selection, A/D and D/A conversion,
interlace/de-interlace processing, modes conversion, OSD and low-voltage differential output, ect.
And it also has functions of audio selection, processing and MCU.

The video signal via MST9U88L processing, output 4 pairs differential signal and 1 pair clock
signal for LCD panel display. Video signal of AV1, AV2, S-VIDEO and TV via initial selection and
processing, output video signal of AV-OUT, after double video amplifying, it will be sent to AV-OUT.

Audio signal via MST9U88L processing, output two ways; one way will be sent to sound
amplifier NA6(MP7722DF) amplifying, then sent to speaker. At the same time, it also sent to
earphone sound amplifier N350(BH3547F), after amplifying then sent to earphone. Another way will
be sent to D/A converter NS6(CS4344) through I2S bus, convert to analog sound signal L/R output
through AV-OUT.

6

Block diagram

TUNER

Pre-IF

IF

HDMI

PC

HD1/HD2

AV1/AV2/

TV-Video

L/R-DVI/PC

EDID

EDID

EEPROM

HDCP
KEY

Serial flash

DDR

MST9X88L

Power
controlMeg8

I/O port

P

A

N

E

L

L/R-HD1

L/R-HD2

L/R-AV1

L/RAV2

TV-SIF

L/R-MUX

4052

I2S

DAC

CS4344

L/R-OUT VIDEO-OUT
AV OUT

2 multiple
video amplify

7

Earphone amplifier

Earphone

D class amplifier
MPS7722

Speaker

IC block diagram

1. MST9U88L

The MST9U88L is a high performance and fully integrated IC for multi-function LDC monitor/TV with
resolutions up to SXGA/WXGA. It is configured with an integrated triple-ADC/PLL, an integrated
DVI/HDCP/HDMI receiver, a multi-standard TV video and audio decoder, a video de-interlacer, a
scaling engine, the MStarACE-3 color engine, an on-screen display controller, an 8-bit MCU, and a
built-in output panel interface. With external frame buffer, 3-D video decoding and processing are
fulfilled for high-quality TV application. To further reduce system costs, the MST9U88L also
integrates intelligent power management control capability for green-mode requirements and
spread-spectrum support for EMI management.

8

Pins description:

4, 5, 7, 8, 10, 11, 1, 2: HDMI input

16, 17: horizontal/vertical synchronous input

27, 25, 22: RGB input

30, 32, 35: YpbPr2 input

41, 44, 46: YpbPr1 input

48, 49: S-VIDEO input

54: AV1-V input

55: AV2-V input

57: TV-CVBS input

59: CVBS output(AVOUT-V)

71, 72: VGA-L/R input

73, 74: AV1(S)/AV2/ YpbPr1/ YpbPr2-L/R input

178: search program synchronous test input

188: HDMI hot-plug test output

189: image switch output

192: backlight control output

193: panel voltage contort output

85, 86: L/R output

234,236,238,239: I2S bus(AVOUT-A)

199-208: 4 pairs differential signal and 1pair clock signal output

174: SDA

175: SCL

2. R2S10401

R2S10401SP is a semiconductor integrated circuit consisting of PLL split-carrier VIF/SIF signal
processing system compliant with PAL.

9

10 11

Pin description:

1, 2: VIF input 10: TV-SIF output

23: SIF input 17: SDA

7: TV-CVBS output 18: SCL

3. MP7722DF

The MP7722 is a stereo 20W Class D Audio Amplifier. It is one of MPS’second generation of fully
integrated audio amplifiers which dramatically reduces solution size by integrating the following:
180mΩ power MOSFETs
Startup / Shutdown pop elimination
Short circuit protection
Mute / Standby
The MP7722 utilizes a single ended output structure capable of delivering 2 x 20W into 4Ωspeakers.
MPS Class D Audio Amplifiers exhibit the high fidelity of a Class A/B amplifier at efficiencies greater
than 90%. The circuit is based on the MPS’ proprietary variable frequency topology that delivers low
distortion, fast response time and operates on a single power supply.

12 13

Pin description:

1, 7: L/R input

19, 14: L/R output

6, 10: mute control input

Wiring diagram

down

up

down

up

IF adjustment

down

up

14

Trouble shooting

1. Fault clearance

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

below.

1.1 Antenna (signal):

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

z Poor signal

z Check if there are failures with the electrical connector or

the antenna.

z Check if the antenna is properly connected.

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

z 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

1.2 TV set:

Symptoms Possible cause

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

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

Deterioration of color phase or color

tone

Screen position or size is not proper z Check is the screen position and size is correctly set up.

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

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

z Possibly due to interference from automobile, train, high

voltage transmission line, neon lamp etc.

z Maybe there is interference between antenna and power

supply line. Please try to separate them in a longer

distance.

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

properly to the connector.

z Check if interfered by other equipment and if interfered

possibly by the equipment like transmitting antenna,

non-professional radio station and cellular phone.

into the socket.

been switched on. (As can be indicated by the red LED at

the front of the TV set)

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

source than the station

z Check if it’s connected to the wrong terminal or if the input

mode is correct.

z Check if the signal cable connection between video

frequency source and the liquid crystal TV set is correct.

z Check if all the picture setups have been corrected.

crystal TV set and make proper adjustment according to the

15

signal types.

Picture too bright and there is

distortion in the brightest area

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 z Check if the antenna cable is correctly connected.

No sound z 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.

z Check if the contrast setting is too high.

z Possibly the output quality of DVD broadcaster is set too

high.

z It maybe also due to improper terminal connection of the

video frequency signal in a certain position of the system.

z Check if the setting for the brightness is too high

z Possibly the brightness grade of DVD player (broadcaster)

is set too high.

z Check if the cable is disconnected.

z Check if it’s connected to the proper terminal or if the input

mode is correct.

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

not correctly identified and VGA format is beyond the

specified scope.

z Check if the batteries are installed in the reverse order.

z Check if the battery is effective.

z Check the distance or angle from the monitor.

z Check if there is any obstruct between the remote control

and the TV set.

z Check if the remote control signal- receiving window is

exposed to strong fluorescence.

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

has received the video signal correctly.

z Of if it has received the right video signal.

z Check if the sound volume is set to minimum.

z Make sure the earphone is not connected.

z Check if the cable connection is loose.

z 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

16

2. Troubleshooting guide

2.1. No raster

Turn-on power supply, check

if the red indicator is light in

the STANDBY?

no

Check if X303 PIN3(5V) of

main board is normal?

no

Check STANDBY circuit of

power supply board

Replace 01 board

Check the power

board

no

no

yes

Press POWER button on the

unit or remote sensor control

and check the indicator.

blue

Check if the PIN27of X304 on

01 board is high-level?

yes

Check if Va, Vs of X5203, X5204

on power board is normal

no

Replace N102

yes

Check the panel

red

Check if the PIN11 of X303 in

main board is high-level?

yes

Check power

supply board

17

2.2. Raster, but no picture

Check if the unit button

and remote control

operation?

yes

no

no

Replace

main board

no

Enter factory-menu,

initialization EEPROM,

then turn off the TV,

turn on again, display

picture?

Adjust main board

Does display OSD

menu in screen when

press menu button?

yes

yes

again

yes

Replace TUNER1

yes

Check if the all channels

have no signal?

no

Which is no signal

of channels

TV

Check if 1VPP signal

and noise wave of

XB201 11# on the TV

board?

no

Check if output IF

no

signal of TUNER1

(pin 11) is normal?

yes

Check IF (NZ100)

and its periphery

HDMI/VGA/YPRPB

Replace

main board

18

2.3.no sound (TV input)

Check if PIN2, 8, 13 and

18 voltage of NA6 is

normal?

no

Check power board

yes

Check PIN3 and

PIN7 output wave of

NA6

no

Check PIN10 wave of

NZ100

no

Check PIN11 wave of

TUNER1

no

Replace TUNER1

yes

yes

yes

Replace NA6

Replace NS4

Replace NZ100

19

APPENDIX-A: Main assembly

NAME NO. MAIN COMPONENT AND it’S NO.

Analog board 667.HSHU31-53 NZ100

NA6

Main board 667.HIHU31-01 NS4

Trans-connection board 667.32HU25-46

Keypad board 667.S42HU31-05

IR receiver board 667.S42HU31-09

Power filter board 667.S42HU31-51

Power board 667.SIHU31-20

Remote control 301.Y37HU32-46 RC-Y46

Panel 335.42027-00 PDP42X4

R2S10401 (353.10401-10)

MP7722DF (353.77220-10)

MST9U88L (353.09880-10)

603-PH42HU31-10
Ver.1.0