Philips DVP520 - Page 19

4-10
No video picture, no sound.
Change C1, D1 and R1.
No video picture,
no sound.
Check whether the reset circuit
consisting of C1, R1 and D1 is
normal (at a high level for tens o
f
milliseconds
,
then constantl
y
at 0V
)
.
Check whether there is
27MHz si
g
nal out
p
ut.
Check whether there is
93MHz signal from R82.
Check the loaded circuit
Crystal oscillator Y1 and
peripheral components
are defected or eroded.
Check whether short-circuit
or bad solder on U7, U8 or
U9, SDRAM, U6 U7.
Check whether short-circuit and
bad solder on Pin Y1 and Y6 of U4
to the subsequent filter circuit.
No
No
No
No
No
Yes Yes
Yes
Yes
Yes
Reconnect the component in
short-circuit
Check U4.
Yes
No
27M waveform
SDRAM (R82 SDCLK) waveform
Trouble shooting chart
Check whether all the voltages
from the power board to the
decoder board are normal.
CVBS(R85 point) waveform