Friday, November 11, 2016

Kawa PDP42V18HA - ATSC-NTSC - plasma display – working principle – password unlock

Almost all plasma displays’ functions are similar.  
Basic Operations & Circuit Description
MODULE
There are 1 pcs panel and 8 pcs PCB including 2 pcs Y/Z Sustainer board, 2 pcs Y Drive
board, 2 pcs X (left and right) Extension PCB, 1 pcs Control (Signal Input) and 1 pcs Power board in the Module.
SET
There are 4 pcs PCBs including, 1 pcs Keypad board, 1 pcs
Remote Control Receiver board, 1 pcs Main (Video) board, and 1 pcs ATSC board in the SET.
Basic operation of Plasma Display
1. After turning on power switch, PSU board sends 5Vst-by Volt to Main IC MT8202 waiting for ON signals from Key Switch or Remote Receiver.
2. When the ON signal from Key Switch or Remote Receiver is detected, MT8202 will send RLY ON and VS ON signals to PUS B/D. Then PSU B/D sends 5Vsc, 9Vsc, 24V to PCBs working. This time CONTROL Board will send signals to Panel by Z/Y SUS Board, OSD on the panel and display available signal. If the audio signals input, them will be amplified by Audio AMP and transmitted to Speakers.
3. If some abnormal signals are detected (for example: over bolts, over current, over temperature and under volts), the system will be shut down by Power off.
PCB function
1. PSU B/D:
(1). Input voltage: AC 120V, 60Hz.
(2). To provide power for PCBs.
2. VSC (Main) board: To converter S signals, AV signals, Y Pb/Cb Pr/Cr signals, HDMI signals and D-SUB signals to digital ones and to transmit to Control board.
3. Control board: Creates signal processing and order of many FET on/off of each DRIVE B/D with R, G, B each 10 bit input.
4. Y-Sustainer board: Generates SUSTAIN, RESET Waveform, VSC (SCAN) voltage and supplies it Y DRIVE B/D.
5. Y-Drive board:
(1). This is a path to supply SUSTAIN, RESET waveform which made from Y SUSTAIN B/D to Panel through SCAN DRIVER IC.
(2). Supply a waveform that select Horizontal electrode (Y SUSTAIN electrode) sequentially.
6. Z-Sustainer board: Make SUSTAIN PULSE and ERASE PULSE that generates SUSTAIN discharge in panel by receiving LOGIC signal from CONTROL B/D.
7. X (left and right) extension board: Receiving LOGIC signal from CONTROL B/D and make ADDRESS PULSE (generates Address discharge) by ON/OFF operation, and supplies this waveform to COF (data).
8. ATSC Board: Receiver and converter ATSC TV signal to transmit to main board.
PCB failure analysis
1. CONTROL :
a. Abnormal noise on screen.
b. No picture.
2. VSC (MAIN) :
a. Lacking color, Bad color scale.
b. No voice.
c. No picture.
d. Abnormal noise on screen.
3. PSU: No picture, no power output.
4. Z - Sustainer:
a. No picture.
b. Color not enough.
c. Flash on screen.
5. Y – Sustainer: Darker picture with signals.
6. Y/Z – Sustainer: The component working temperature is about 55°C.  If the temperature rises abnormal, this may be a error point.
7. ATSC: NO ATSC TV signal.
Display dot diagram
Image Sticking
The fluorescent substance used in the plasma module loses its brightness with the lapse of lighting time. This deterioration in brightness appears to be a difference in brightness in relation to the surroundings, and comes to be recognized as image sticking.
In other words, the image sticking is defined as follows: when the same pattern (of the fixed display) is displayed for a long time, a difference in brightness is caused around the lighting area and non-lighting area due to deterioration in the fluorescent substance.  When the present pattern is changed over to another one, the boundary comes to be seen between the lighting area and non-lighting area due to difference in brightness in the pattern shown shortly before changeover. If this conditions is accumulated, the boundary or image sticking comes to be seen with the naked eyes.
Practical value for Image sticking
The relationship between integrated lighting time and brightness in this plasma module is described in the attached material. In particular, the deterioration in brightness tends to be accelerated up to 100 hours in the initial period. In the initial period, the fixed display of patterns particularly tends to cause image sticking. The practical value for image sticking is difficult in concrete numerals. As described below, you are advised to take proper measures to make the occurrence of image sticking as slow as possible.
Proposed measures taken to relieve image sticking
So long as there is the reduction of brightness in the fluorescent substance, it is impossible to avoid the occurrence of image sticking. Therefore, to relieve image ticking,  a method of entering an image input that may ensure reluctance to the generation of the difference in brightness reduction among the displayed dots.
The images from TV broadcasting involve a high rate of motion picture displays. Therefore, there is less chance of being a cause of difference in brightness reduction among the cells. Even when the fixed patterns are displayed, they generally last for a few minutes. Since the same pattern is less liable to be displayed, there is
almost no influence toward image sticking.
If the fixed patterns tend to be displayed for a long time, however, there occurs a substantial imbalance between the lighting and non-lighting areas, thus causing a difference in brightness as a result. In this document, some proposals of installation, paying attentions to the two points: the reduction of difference in brightness achieved by integrated lighting time leveling and the method of edge smearing to make image sticking hard to be discerned.
The result from these proposals can, however, greatly depend on the contents of images and the operating environment. Therefore, we consider that it is essential to take the suitable measures in consideration of the operating environment.
Example of Proposal 1: The display position is moved while the fixed display pattern is changed over, or it is scrolled during the display.
Example of Proposal 2: If possible, a pattern of complementary color is incorporated (for integrated time leveling).
Example of Proposal 3: The fixed pattern and the motion picture display are reciprocally exchanged, in order to minimize display period of the fixed pattern.
Example of Proposal 4: During operation, the brightness of screen is suppressed as low as possible. For the display patterns, characters are indicated not on the black ground (non-picture area) but on the colored ground (mixture of R, G, B recommended).
Secular change in brightness
The life of brightness, defined as the reduction to half the initial level, is more than 25 thousand hours on average.
Conditions: All white (100% white) input at an ambient temperature of 25°C.
However, this lifetime is not a guarantee value for life and brightness. It should be recognized simply as the data for reference.
Main IC Specifications
M13S128168A (ESMT)
2M x 16 Bit x 4 Banks Double Data Rate SDRAW
MT5111CE
Single-Chip HDTV/CATV Demodulator
MT5351
MT5351 is a DTV Backend Decoder SOC which support flexible transport demux, HD MPEG-2 video decoder, MPEG1,2, MP3, AC3 audio decoder, HDTV encoder.  MT5351 is powered by ARM 926EJ with 16K I-Cache and 16K D-Cache. It can support 64Mb to 1Gb DDR DRAM devices with configurable 32/64 bit data bus interface.
MT8202
MT8202G is a highly integrated Single-Chip for LCD TV supporting video input and output
format up to HDTV. It includes 3D comb filter TV decoder to retrieve the best image from
popular composite signals.
MT8293
HDMI PanelLink Cinema Receiver
R2S15102NP
Digital Power Amplifier R2S15102NP
WM8776
24-bit, 192kHz Stereo CODEC with 5 Channel I/P Multiplexer.
If you forget your V-Chip Password
Omnipotence V-Chip Password: 8202
Using the “Change Password” item
When enter the “V-Chip” menu, select “Change Password”.
Press
or button to highlight the “Change Password” item.
Press Enter button to confirm and pop up a menu
Use 0~9 buttons input the omnipotence password(8202), then Press Enter button to enter and pop up a menu.
Use 0~9 buttons input your new password.
Press
button to move to confirm blank.
Use 0~9 buttons input your new password again.
Press Enter button to confirm
-Suggest: Change to your familiar Password again.