9.4.Local screen failure
Plasma display may have local area failure on the screen. Fig - 1 is the possible defect P.C.B. for each local area.
Fig - 1
9.5.D-Board
9.5.1.OUTLINE
D board is consists of Analogue and Digital signal process, Discharge control and Micro control block.
D-board is operated by supply voltages of 3.3V, 5V, 13,5V and Standby 5V , RGB analogue (0.7Vp-p) and Sync. Signal.
D-board output parallel data video signal with control signal for the data driver circuit, Discharge control signal for Scan and Sustain
drive circuits and Micro control signals.
9.5.2.MAIN IC OPERATION
IC9007 ~ 9009 A/D Converter
RGB analogue signals are converted to 8 bits digital signal.
IC9204, IC9254 FORMAT CONVERTER (LSI33)
Number of Horizontal line of input signals are converted to 768 lines.
This IC uses two clock lines, one is 15M 55MHz for input signal (ICK) and other one is 25M to 40MHz for out put signal. (OCK)
IC9400, IC9450 PLASMA AI (LSI27)
At first input 8 bit signal data is memorized into two field memory (IC9402, IC9403) (IC9452, IC9453), Plasma AI analyze APL
level and distribution of dark and bright components.
Plasma AI re-arrange 8 bit signal data to 12 bit signal data.
This IC also insert OSD (On-Screen Display signal) from Micro.
IC9501, IC9551 SUB FIELD PROCESSOR
R,G and B 12 bit signal data is layout to fit with each electrodes of panel.
One field signal data is separated to upper 384 lines and lower 384 lines.
Both upper and lower signals are again separated odd and even number line and output.
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ACEC
