AKAI PDP-4206EA PLASMA TV - PCBs - LOCATION & FUNCTIONS - BASIC
OPERATIONS OF A PLASMA DISPLAY - FAULTS DUE TO CIRCUIT BOARDS - HOW TO
SEPARATE COF
1. Power:
- Input voltage: AC 110V~240V, 47Hz~63Hz. Input range: AC 90V(Min)~265V(Max) auto regulation.
- To provide power for PCBs.
To converter TV signals, S signals, AV
signals, Y Pb/Cb Pr/Cr signals, DVI signals and D-SUB signals to digital ones
and to transmit to Control board.
3. Control board:
Dealing with the digital signal for output
to panel.
4. Y-Sustainer / Z-Sustainer board:
- Receiving the signals from Control and high voltage supply.
- Output scanning waveform for Module.
5. Y-Drive board:
Receive signal from Y sustainer, output
horizontal scanning waveform to the panel.
6. X (left and right) extension board:
Output addressing
signals.
7. Tuner/Audio Board:
- Amplifying the audio signal to the internal or external speakers of which selected.
- To convert TV RF signal to video and SIF audio signal to Main board.
Receiver and converter ATSC TV signal to
transmit to main board.
BASIC OPERATIONS
- After turning on power switch, power board sends 5Vst-by Volt to Main IC MT8205 waiting for ON signals from Key Switch or Remote Receiver.
- When the ON signal from Key Switch or Remote Receiver is detected,MT8205 will send ON Control signals to Power. Then Power sends (5Vsc, 9Vsc, 12Vsc, 24V and RLY ON, Vs ON) to PCBs working. This time VIF will send signals to display back light, OSD on the panel and start to search available signal sources. If the audio signals input, them will be amplified by Audio AMP and transmitted to Speakers.
- If some abnormal signals are detected (for example: over volts, over current, over temperature and under volts), the system will be shut down by Power off.
FAULTS due to COF damage
COF is the most important component in the PDP module. Even a little imperfection of COF can make a
serious screen problem.
COF
X/BD
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).
HOW TO SEPARATE COF
Z Sustain B/D
Make SUSTAIN PULSE and ERASE PULSE that generates SUSTAIN
discharge in panel by receiving LOGIC signal from CONTROL B/D. This waveform is supplied to panel through
FPC(Z).
# composed with IPM,FET,DIODE, electrolytic capacitor ,E/R
coil.
# IPM (Intelligent Power Module). ## E/R(Energy recovery)
FPC SEPARATING
Y drive B/D
- This is a path to supply SUSTAIN ,RESET waveform which made from Y SUSTAIN B/D to panel through SCAN DRIVER IC.
- Supply a waveform that select Horizontal electrode (YSUSTAIN electrode) sequentially. Potential difference is 0V between GND and Vpp of DRIVER IC in SUSTAIN period. Being generated potential difference between GND and Vpp only in SCAN period.
- In case of 42” V6 use DRIVER ICIC 8 EA (TOP, BOTTOM: each 4EA)
Y SUSTAIN B/D
Generates SUSTAIN,RESET waveform, Vsc(SCAN)voltage and
supplies it Y DRIVER B/D.
Composed with IPM,DIODE, electrolytic capacitor ,FET.
CONTROL BOARD
Creates signal processing (Contour noise, reduction ISM,..) and
an order of many FET on/off of each DRIVER B/D with R,G,B each 8bit input.
Use 3.3V/5V 2 kinds of power.
DC/DC CONVERTER
Being impressed 5V, Va ,Vs, DC/DC converter makes
5V,Va,Vs,Vset_up,Vsc which is essential for each B/D.
There is no DC/DC B/D in model 40/42 (1 POWER B/D).
50 / 60 embedded DC/DC B/D separately because of high power consumption.
FPC (Flexible Printed Circuit)
- Supply a driving waveform to PANEL by connecting a PAD electrode of PANEL with PCB(Y and Z). There is two type of this for Y B/D. One is single-sided, another is double-side. These are having pattern on it. For Z B/D, there is no pattern , single-sided, and Beta type (all of copper surface).
For connecting a Logic signal between B/D and B/D.
There is 0.5mm pitch,50pin type 1mm pitch ,30pin type
IPM(Intelligent Power Module)
Composition
HEATSINK,CAPACITOR
DIODE
IC LINEAR
RESISTORTANSISTOR,FETS.
Description
Attached at Z B/D and Y B/D, make Sustain waveform.
Sustainer : supply a square wave to panel to make a video.
COF (Chip On Film)
- Supply a waveform which made from X B/D to panel and select a output pin that is controlled by COF when be on or off.
- 96 output pin per IC. The more the resolution higher, the less spare space where can set IC on it in B/D. without using IC PACKAGE, we can use a BARE IC , so we can get IC with LOW COST. Because we do not solder IC on PCB directly, a soldering defect rate decrease.
