PDP PH-42HU31 User manual

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

1
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.
Attention: This service manual is only for service personnel to take reference with. Before
servicing please read the following points carefully.

2
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

3
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
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
Check DDC, HDCP KEY, FLASH and POWER control IC
Factory initialization setup
IF channel AFT voltage of TV and AGC voltage
White balance adjustment
Performance check
Preset ex-factory
VGA, YPbPr ADC correction

4
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)

5
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

6
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.

TUNER
HDMI
AV1/AV2/
HD1/HD2
Pre-IF
TV-SIF
IF
PC
L/R-HD2
4052
TV-Video
L/R-DVI/PC
L/R-HD1
L/R-MUX
MST9X88L
P
A
N
E
L
I/O port
KEY
Power
controlMeg8
DDR
Serial flash
HDCP
KEY
EEPROM
DAC
CS4344
2 multiple
video amplify
L/RAV2
L/R-AV1 L/R-OUT VIDEO-OUT
AV OUT
D class amplifier
MPS7722
Earphone amplifier
I2S
EDID
EDID
Earphone Speaker
Block diagram
7

8
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.

9
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.

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:
180mΩpower 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

down
up
down
up
down
up
IF adjustment
Wiring diagram
14

15
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 zBad status in signal receiving
zPoor signal
zCheck if there are failures with the electrical connector or
the antenna.
zCheck if the antenna is properly connected.
Fringe in picture zCheck if the antenna is correctly oriented.
zMaybe there is electric wave reflected from hilltop or
building.
Picture is interfered by stripe shaped
bright spots
zPossibly due to interference from automobile, train, high
voltage transmission line, neon lamp etc.
zMaybe there is interference between antenna and power
supply line. Please try to separate them in a longer
distance.
zMaybe the shielded-layer of signal wire is not connected
properly to the connector.
There appear streaks or light color
on the screen
zCheck if interfered by other equipment and if interfered
possibly by the equipment like transmitting antenna,
non-professional radio station and cellular phone.
1.2 TV set:
Symptoms Possible cause
Unable to switch the power on zCheck to see if the power plug has been inserted properly
into the socket.
No picture and sound zCheck 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)
zSee if it’s receiving the signal that is transmitted from other
source than the station
zCheck if it’s connected to the wrong terminal or if the input
mode is correct.
zCheck if the signal cable connection between video
frequency source and the liquid crystal TV set is correct.
Deterioration of color phase or color
tone
zCheck if all the picture setups have been corrected.
Screen position or size is not proper zCheck is the screen position and size is correctly set up.
Picture is twisted and deformed zCheck to see if the picture-frame ratio is properly set up.
Picture color changed or colorless zCheck the “Component” or “RGB” settings of the liquid
crystal TV set and make proper adjustment according to the

16
signal types.
Picture too bright and there is
distortion in the brightest area
zCheck if the contrast setting is too high.
zPossibly the output quality of DVD broadcaster is set too
high.
zIt 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
zCheck if the setting for the brightness is too high
zPossibly the brightness grade of DVD player (broadcaster)
is set too high.
No picture or signal produced from
the displayer if “XXX in search”
appears.
zCheck if the cable is disconnected.
zCheck if it’s connected to the proper terminal or if the input
mode is correct.
There appears an indication -
“outside the receivable scope)
zCheck if the TV set can receive input signal. The signal is
not correctly identified and VGA format is beyond the
specified scope.
Remote control cannot work
properly
zCheck if the batteries are installed in the reverse order.
zCheck if the battery is effective.
zCheck the distance or angle from the monitor.
zCheck if there is any obstruct between the remote control
and the TV set.
zCheck if the remote control signal- receiving window is
exposed to strong fluorescence.
No picture and sound, but only
hash.
zCheck if the antenna cable is correctly connected, or if it
has received the video signal correctly.
Blur picture zCheck if the antenna cable is correctly connected.
zOf if it has received the right video signal.
No sound zCheck if the “mute” audio frequency setting is selected.
zCheck if the sound volume is set to minimum.
zMake sure the earphone is not connected.
zCheck if the cable connection is loose.
When playing VHS picture search
tape, there are lines at the top or
bottom of the picture.
zWhen 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

17
2. Troubleshooting guide
2.1. No raster
Turn-on power supply, check
if the red indicator is light in
the STANDBY?
Check if X303 PIN3(5V) of
main board is normal?
Check STANDBY circuit of
power supply board
Press POWER button on the
unit or remote sensor control
and check the indicator.
Check if the PIN27of X304 on
01 board is high-level?
Check if the PIN11 of X303 in
main board is high-level?
Check power
supply board
Check if Va, Vs of X5203, X5204
on power board is normal
yes
no
no
red
blue
no
yes
Replace 01 board
no yes
Replace N102
Check the panel
Check the power
board
no
yes

18
2.2. Raster, but no picture
Check if the unit button
and remote control
operation?
Check if the all channels
have no signal?
Replace
main board
Enter factory-menu,
initialization EEPROM,
then turn off the TV,
turn on again, display
picture?
Adjust main board
again
Which is no signal
of channels
Replace
main board
Check if 1VPP signal
and noise wave of
XB201 11# on the TV
board?
Check if output IF
signal of TUNER1
(pin 11) is normal?
Replace TUNER1
Check IF (NZ100)
and its periphery
no
yes
yes
HDMI/VGA/YPRPB
TV
yes
no
no
no
yes
Does display OSD
menu in screen when
press menu button?
yes
no
yes
no