Xoceco PS-42D8(B, S), PH-42D8 Schematic

COLOR TELEVISION

PS-42D8 B PS-42D8 S

PH-42D8

CONTENT

Safety instructions………………………………………………………………………..… Method of Debugging ……………….…………………………….…….………………… Method of software upgrading ………………………………………….………………… Briefing on the operation principle of the plasma TV series PS and PH …………….

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

Distribution of the Circuit Board of Different Screens and their Functions ……….… PCB parts and number ……………………………………………………………………. Diagnosis for Plasma Screen of PS and PH ………………………………………..…. Troubleshooting guide………………………………………………………………..…… Schematic diagram…………………………………………………………………………..… Exploded views………………………………………………………………..……….…..

1 4 5 7 15 18 19 20 23 28 43

Note: This maintenance manual is intended only for t he reference of the maintenance people. Please pay attention to the following points bef or e car rying out the maintenance work.

Safety Instructions

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 t he M ai nt enance & 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 w ork on PDP module whe n

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 w ith t he circuit r y of the working

module or metal parts. That’s because within a short time relatively high voltage st ill 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 . O therwise 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 t he 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 are quite a number of circuits in PDP that are integrated ones. Please be on guard against static electric ity. During maintenance operation be sure to cover yours el f with ant i-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.

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 drivi ng 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 w ith anti-mois ture bag and hav e the m piled an d stored in one place. The environmental conditions are tabulated as below:

Temperature Scope for

operation Scope for storage -15~60centigrade Humidity Scope for

operation 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 t hat t here

0~50centigrade

20%~80%

is reduced density of f luorescent pow der in t he for mer. On the other hand, even if ch anges t ake 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. Howev er please try as much as possible to avoid showing a still picture of high brightness for a long time during operat ion.

1.16 As a digit alized 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 t he bright ness for the t wo adjacent levels is uneven. This is caused by t he reuse of sub-field, the display of load rectification and the eletrolyzation.

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 sh ould be taken not t o use too long or too big screw.

1.20 Care must be taken to guard aga inst dust durin g assembling or dismantl ing, espe cially 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 ta ke 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.

2.“Criterion for Identifying the Defects on Screen”

The PDP produced by our Company at present uses the following criterion for identifying the defective points:

MODEL PS-42D8 B/S,PH-42D8:

There may appear three kinds of defective points for this m odel as shown in Fig.1, i.e.bright spot

(remain bright); dark spot (non-illuminating) ; flickering spot (cont inuously flickering).

However they should not exceed the specification as in table 1. O t herw ise t he product shall

be deemed as sub-standard.

Figure 1 Defective Points

Zone B

Zone A

W/4 W/2

H/4

H/2

H/4

W/4

Table 1 Criterion for Three Kinds of Defective Points

Kind Area A Area B Remark

Dark spots No more than 2 No more than 8 Bright spot No more than 1 No more than 2

Flickering spot No more than 1 No more than 2

Total number of

defective points in A

and B shall not exceed

8. The distance

between two defective

points shall not be

shorter than 15mm.

Method of Debugging

For Models PS-42D8 B/S PH-42D8, the debugging part lies only in the white balance adjustment. Nothing else should be adjusted and the maintenance software supplied for after-sale purpose has normally shielded the value of white balance i.e., no more adjustment is needed when upgrading the software. In case of special circumstances where the main board is replaced f ollowing method can be adopted:

1.The white balance ad ju st ment is made resp ectiv ely in t hree way s - TV/AV,VGA,Y pbPr. First adjust

TV/AV, then VGA and YpbPr at the last.

2. Select corresponding channels respectively. After successively press the keys on the production plant’s remote control (the key at the right hand lower corner doesn’t show up), go on to press the left key, right key, confirmation key on the small keyboard one by one and then it’s possible to enter the menu set up in the plant.

3. Use the right key to select and calibrate the menu. The white balance adjustment and YpbPr white balance adjustment are for the purpose of white balance adjustment. For the white balance adjustment of TV/AV and VGA it’s OK just directly adjust the first item whereas for YpbPr adjust the second item.For the white balance adjustment of TV/AV and VGA: select the item of “white balance adjustment” from the menu. W hen it’s entered (as shown in the fig. Below), keep RCUI immovable and adjust GCUT and BCUT so as to adjust the white balance of the dark area. For the adjustment of white balance of the bright area, keep RGR immovable and then adjust GGRV and BGRV. Repeat the above steps several times until the picture is normal in white balance.

4. For the white balance a djustment of YpbPr: select the item of “white bala nce adjust ment” from th e menu. When it’s entered (as shown in the fig. Below), adjust RCUT and BCUT and it’s done.

5. Note: Except for the two items in the plant setup menu as above used f or the white balance adjustment and the items 5,6,7 (for test of pattern, color collocation and degree of pure gray) in the calibrated menu that can be used to shoot trouble, no adjustment should be made for the other items. Otherwise it may cause abnormality to the set. The internal test signal of PW181 can be used for troubleshooting.

Method of softwar e upgrading

The plasma TV models PS -42D8 B/S and PH-42D8 launched by our company are equipped with

RS-232 interface for upgrading that is carried in the steps below:

Select a connection wire o f serial port (see the figure below) w hich i s required t o hav e a notch o n its

both ends and also the pins 2 and 3 on the two ends are cross-connected.

1.Use the serial port connection wire to connect PC with PDP and set PDP to the off position.

2.Open the folder of the upgrading software and double click the FlashUpgraderNT (on condition of window 2000/XP/NT)

or the FlashUpgrader (on condition of window 98)

After running the programs the following interfaces w ill appear :

Based on the features of computer set up the serial port (COM Port) and select corresponding serial port (if it’s not possible to burnt-write other serial port can be used instead). Baud-select 115200 and then select Reset Target After Download. Hit flash press button and it’s ready to operate. For the setup of other items please refer to the figure above (already defaulted by the system so it’s normally unnecessary to alter)

1. Switch on PDP and it begins to run the burnt -w rit e program;

2.Once it’s over with burnt-write, the cancel pushbutton will become flash. Switch off the main power and then to switch on the TV set again.

Note: Do not switch the power or t he set off in the course of burnt-writing. Otherwise it

may result in the inability of the flash to burnt-write again.

Briefing on the operation princi ple of the plasma TV series PS and PH

Plasma plane screen technology represents the state-of-the-art and it’s also the best choice for high quality picture and large purely place screen. Plasma display screen PDP is a display unit employing gas discharge. This screen uses plasma tube as its light emission component. The faceplate (panel)of PDP consists of many image elements (plasma tubes) for example, the series PS ,PH pdp now on the market consists of 852*480 image elements. Each image element in turn consists of three kinds of image sub-elements. Each image element is actually a plasma tube. These tubes are present respectively in red, green and blue colors, as shown in fig. I. Each small chamber that corresponds to each plasma tube is filled with neon and xenon gases. After applying high voltage between the plasma electrodes, the gases in the small chambers of the plasma tubes sealed in the two layers of glass will produce ultraviolet so as to excite the three basic co lor (red, green and blue) fluorescent powder to emit visible light. Each plasma tube acts as an image element. From the composition of these image elements in different brightness, darkness and colors result the pictures and images of various grays and colors, which is very similar to the light emission of display tube. Plasma technology is obviously different form other display methods and is more advanced in structure and formation. Its working principle is similar to normal daylight lamp. The TV color picture is composed of the light emitted from various independent fluorescent powder image elements and therefore the picture is fresh and gaily colored, bright, clean and clear. Furthermore the most outstanding feat ure of plasma TV is that it can be made super thin and it’s easy to make TV sets of more than 40” with completely plane big screen but in thickness less than 100 mm (Our Model PS-42D 8 is only 79mm thick and it’s the thinnest in the m arket at present.)

Plasma TV model PS-42 D8 B/ S and PH-42 D8 serie s of XO CECO is des igned and dev elope d by XOCECO itself. In terms of the main CMOS chip this series of TV set employs PW181 made by Pixelworks Company.

Among which:video decoder:VPC3230 Non-interlace conversion:PW1230 Ad conversion and DVI interface :AD9887 Audio treatment:MSP3440 Sound power amplification:D type power amplification of TI : Tpa3001 3D Y/C separation:uPD64083 CCD/V-CHIPdecoder:Z86229(For North America only)

2. the basic work process flow of model PS and PH series:

2.1. control part

This TV model is based on dual MCU control of which the main MCU is PW181(N501, taking care of the operation of various chips (includin g image treatment , channel sw itching, image display etc.), infra red remote control receiving, the standby control, the control of auxiliary CPU, menu display, debugging of picture effects and other major functions. The auxiliary CPU is SDA555X(NM5, which is responsible for sound treatment (includin g v olu me adjust ment, cont rol of a lt and base sou nd, st ereo decod e), st atio n searching control, push button, separation of 3D Y/C (valid only for system N) as well as the CCD/V-CHIP decoding for the text for oversea sale TV sets etc. Connection between two MCU is made by means of three pins of X708, i.e., INT (int errupt ion) , S1(RX D), S2(TXD)

2.2. Volume of sound

This model employs double integrated tuner (including high frequency and m edium amplification circuits). The signal received by antenna is fed to the main tuner, TUNER1, which contains a high frequency distributor, from which RF signal is shunt to supply to TUNER3 for use. Pin 14 of TUNER1 is for the power supply of high frequency distributor (+5v). Tuners are controlled by auxiliary MCU NM5 (SDA and SCL)to select proper channel and carry out correct switching of systems. After high amplification and medium amplification decoding, video signal and audio signal are output. The output signal of TUNER1 is fed into decoder N102 as the display of main picture whereas the output signal of TUNER3 is fed into decoder N302 as the display of the auxiliary picture for dual picture. Audio signal is directly fed into audio frequency processor NM2 MSP3440. At the same time dual way tuners all send their medium frequency signal of the seco nd soun d to NM2 for treat ment (used for decoding o f stereo or automatic sound volume control). NM2 is provided with the switching over device for audio frequency channels. Audio input of VGA/DVI/YprPb of the main board, after the switching-over as selected by N3, is fed together with the audio signal of TV and AV into NM2, where switching over is selected. The selected audio frequency signal is made use of in the following three ways. One way is, after being subjected to the control of volume and alt and base sound, fed separately through left and right sound channels into sound power amplifier TPA3001 for amplification. Then it is fed into the loudspeaker for sound reproduction. Another way is also fed separately through left and right sound channels into earphone power amplifier NM9 TDA7053 for amplification before being output to earphone socket for listening, of which the volume is controlled by PWM signal produced by pin 50 of NM5.The remaining way is output through video board as AV out.

The block diagram of MSP3440 is as follows:

2, 3:SCL and SDA for the control of IC operation;

27,28:output to the right and left channel of sound power amplifier;

33,34:right and left channel of earphone sound;

36,37:AV OUT right and left channel of sound;

47,48:right and left channel of sound fed from main board;

50,51:AV IN right and left channel of sound;

53,54:right and left sound channel of sub-channel TV ;

56,57:right and left sound channel of main channel TV ;

67,69:SIF input of main and sub channel TV

Sound power amplifier TPA3001 is an amplification of mono-channel high efficiency D type power. Under the condition of no heat dissip atio n its output power can be as hi gh as 20 w. It has the functions of over current and overheating protection. Automatic protection comes in when the input to the ground is short-circuited. Then output is stopped. After the removal of short circuit, switch the set again and it restores to normal. Therefore if the set becomes soundless due to the short circuit caused in carelessly pulling out or plugging in the audio frequency wire (it is certainly not recommendable to do so), just switch it on again and no big deal.

2.3.Picture and image:

Y signal of AV and SVHS shares the same chann el. SVHS has pr iorit y. Identification of termin al S is determined by electric level SID fed from SVHS socket to NM5. When the electric level of SID is of hi gh value, the system is identified as SVHS. Signals from TV or AV and YCRCB are altogether fed into digital decoder VPC3230 (sent separately in two ways to N102 and N302). Channel switching is carried out. They are decoded int o 16b it C CIR601 signa l to be fed i nto t he process or of lower l ev el for treat ment . VPC3230 mainly functions to switch over channels, separate Y/C of 4 lines, decoding of colors and adjustment of picture effect.

2.3.1The block diagram of VPC3230 is shown below:

In which: Pin 71 is used for the input of C signal of SVHS;

Pin 72 VIN1 is used for the input of Y signal of CVBS or SVHS of AV; Pin 73 VIN2 is used for the input of TV signal; Pin 75 VIN4 is used for the input of Y signal of YCRCB to synchronously identify YCRCB.

Main channel: The digital YCRCB signal in the form at of CCIR601 after being decoded in N102 is fed into non-interlace processor N204 PW1230 for treatment from alternate-line into non-interlace. VD1_CLK,VD1_HSYNC VD1_VSY N C, VD1_ACTIVE and VD1_ FI ELD sent from VPC3230 is used as a key signal to identify modes. If certain channels become abnormal the corresponding pictures will also become abnormal. In addition to the function PW1230 has to process the signal from alternate-line into non-interlace, it can also function to enhance the picture and convert the movie modes 3:2/2:2. The adjustment of brightness and contrast of the main channel is performed by this chip whereas the adjustment of chroma and definition is performed by N102. The digital 24 bit RGB signal output from PW1230 after treatment is fed into V PORT of N5 01 P W181 for further processing. The signa ls of VCLK (clock) and VVS(field synchronization) and VHS(line synchronization) and VPEN(enable signal)are the basic reference for the image processing of lower level.

For TV set of mono N system, this series has an additional 3D Y/C separation function in the main channel, which is performed by ND02 Upd64083 so as to enhance the quality of the image. In this case the signal flow process of the main channel is different. Video signal and AV/SVHS signal sent from TUNER1 first undergo switching in the switch circuit ND01, then are fed into ND 02 for separation of brightness from col or and outp ut as sig nal Y and C. For N102, no matter whether it’s TV or AV/SVHS, finally the signals are all fed in the form of Y/C into the input port of VIN1and CIN. Yet the setup for the software is somewhat different.

The decoding for the text of main channel or CCD/V-CHIP is performed by auxiliary CPU. Video signal is directly fed to pi n 12 of NM5 for decoding. The decoded text or CCD/V-CHIP signal is output in the form of R, G, B, FB and fed into N102 for character superposing.

Sub-channel:

Signal CCIR601 after being decoded in VPC3230 is directly fed into PW 181 G PORT where direct processing is carried out by PW181. The non-interlace conversion in this channel is performed by the non-interlace processor inside PW181. Relatively speaking, the efficiency of the internal non-interlace processor of PW181 is lower than that of PW1230. Therefore when displaying dual picture the main

picture effect is better than that of sub-picture. The adjustment of brightness, contrast, definition and chroma is performed by N302.

The decoding of CCD/V-CHIP in this channel is specially performed by 21 line decoder N301 Z86229. The deco ded information is superposed onto the image in N302 a lso i n t he form of R, G, B and FB.

For VGA and YPRPB, after the selection in N1 YPRPB1 and YPRPB2 are fed together with N402 for channel selection. The selected signal is fed into the ADC part of N403 AD9887 for A/D conversi on so as to produce 24 bit digital RGB signal to be fed into the G PORT of PW181. The line and field synchronous signal of VGA is directly fed into N403 whereas The line and field synchronous signal of YPRPB is obtained after synchronous separation of Y signal of SOGIN in AD9887 (This signal is input t o N403 pin 108).

Synchronous switching device is shown in the f ol l owing fi gur e:

AD9887 is also provided with DVI input port. The DVI input signal is converted into 48 bit digital RGB signal and sent to G PORT of PW181 for processing. The selection from DVI and VGA/YPRPB is performed by AD9887.Certain organizations for the oversea sales of this TV series h ave been equipped with the capabili ty to decode HDCP. PORTA4 and PORTA5 of PW181 verify the password (cip her key) through bus line with broadcast equipment. Each TV set has its own independent password, which is stored in EEPROM.

The mode identification of VGA or YPRPB is performed by PW181. The identification process is :

When selecting channel si gnal input P W181 preset s t he synchronou s select ion of AD9887 so that it can directly output the required synchronous si gnal for direct feed ing to P W181. The synchronou s signal format is identified inside PW 181. By making cross-reference with the format table pre-stored inside a most similar format is obtained. Then the parameters of this format are called for use in setting up the parameters for modular conversion so t hat it is optimized. At the same time the conversion coefficient of SCALER is confirmed.

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