Daewoo DPC-7900 Series, Serivce Manual

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correctly plugged to the fixed positions, or re-plug them.
B.
Use oscilloscope to measure if Y1 generates 27MHz. If it does not generate
said frequency, and the problems such as cold or hollow soldering have been
ruled out, it maybe Y1 work abnormally . Replace Y1 with a 27MHz
fundamental frequency oscillater.
C
. Check if U
17
(F/W) IC has any problem.
D
. Check if switch
for TFT on/off
is normal; replace a new one if necessary.
E
. If the above actions are not working, replace the Main Board.
Driver Board
B
. Adjust
VR4,VR6,VR1,VR7,VR5
to the appropriate
value
.
A
. Check
VR6,VR4,VR1,VR7,VR5
is using the correct component. Also check if
it’s damaged.
DVD ROM (less likely to happen)
A.
If it is useless to change the main board, then replace the loader.
T22 Video no video / abnormal
Main Board
A.
Remove the cover. Check the main board to see if there is any cold or hollow
soldering and rule out the problem.
B. Remove the top cover, check all flat cables in the system to see if they are
correctly plugged to the fixed positions, or re-plug them.
C. Check RLC following CVBS to see if there is any wrong parts, cold and hollow
soldering, short circuit, broken circuit, broken parts and rule out the problem.
D.
If the above actions do not work, then check U17Pin175 and Pin182 to see if
there is CVBS signals.
E
. If the above actions are not working, replace the Main Board.
T23 S-Video no video / abnormal or black & white
Main Board
A.
Remove the cover. Check the main board to see if there is any cold or hollow
soldering and rule out the problem.
B. Remove the top cover, check all flat cables in the system to see if they are
correctly plugged to the fixed positions, or re-plug them.
C. Check RLC following Y and C to see if there is any wrong parts, cold and
hollow soldering, short circuit, broken circuit, broken parts and rule out the
problem.