DAEWOO ELECTRONICS DPP-42A1GCSB, Service Manual

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English
3-3. SCAN IC(Y DRV B/D : IC1~10) Damage
(1) In case of SCAN IC poor, one horizontal line may open
at screen.
O
Test Point: Enlarge after measuring
GND ~ Output ICT on Y DRV B/D
O
Wave format : As shown fig. 4
(2) Screen may not shown when SCAN IC is damaged by
SCAN IC poor, external electricity or spark.
O
Test Point : Enlarge after measuring
GND ~ Output ICT on Y DRV B/D
O
Wave format : Output wave format isn’t output
(You can see the damage for Y DRV B/D’s
SCAN IC)
(3) In case of shorting the SCAN IC output by a dust, foreign
substance, it may overlap two horizontal lines on screen.
O
Test Point : Enlarge after measuring
GND ~ Output ICT on Y DRV B/D
O
Wave format : As shown fig. 5
3-4. TCP Damage
(1) In case of shorting or opening the IC output of TCP, it may
show one or several vertical lines.
O
Test Point : Enlarge after measuring
Output TP of GND ~ TCP
O
Wave format : As shown output fig. 7
In case of normal wave output, when STB signal is
generated, maintain High output. And when STB signal
is generated again must be fall Low.
But when IC of TCP is poor, STB signal is not generated
Output falls with Low.
Remove SR before measuring because the output TP of TCP
is covered with SR. Insulate again with insulating tape after
measuring.
<Fig. 4 When SCAN IC is poor>
7 us
6 0V
<Fig. 6 SCAN IC Normal Output Wave >
<Fig. 5 When SCAN IC output is short>
<Fig. 7 When IC output of COF is poor>