Philips PDP42V7 series, Руководство по обслуживанию

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Service Modes, Error Codes, and Fault Finding EN 20 LGE PDP 5.
Figure 5-55 SCAN IC normal output
TCPs
1.
In case of shorting or opening of TCP IC output, it may
show one or several vertical lines.
–
Test Point: Output TP of GND-TCP
– Wave format: As shown in figure below. In case of
normal wave output, when STB signal is generated,
the output must maintain "high". When STB signal is
generated again, the output must fall to "low". But
when the TCP IC is damaged, the STB signal is not
generated, and the output falls to "low".
2. In case of a damaged TCP IC or power resistance, the
screen is not shown or discharges partially.
–
Test Point: Output TP of GND-TCP
– Wave format: Output wave is not generated.
Figure 5-56 COF IC output defective
Figure 5-57 TCP normal output
Crystal (CTRL board: X1)
1.
When a crystal is damaged, the screen is not shown.
–
Test Point: Measuring 3-pin of GND-Crystal (CTRL
board: X1).
– Wave format: Output wave is not generated.
2. In case of unusual start-up of the crystal, the screen may
blink.
–
Wave format: As shown in figure below.
– Measurement position: Measuring output 3-pin of
crystal (X1: 100 MHz) on CTRL board (full white
pattern).
Figure 5-58 Crystal normal output
Figure 5-59 Crystal defective output
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