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

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.

1.10 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

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

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)

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

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.

Block diagram

TUNER

Pre-IF

HDMI

HD1/HD2

AV1/AV2/

TV-Video

L/R-DVI/PC

EDID

EEPROM

HDCP KEY

Serial flash

DDR

MST9X88L

Power controlMeg8

I/O port

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

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.

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