Philips SDV434/19, Service Manual

Page: 20 / 44

4-10
No video picture, no sound.
Change C88, and R80.
No video picture,
no sound.
Check if the reset circuit consisting
of C88, R80 and D1 is normal (at a
high level for tens of milliseconds,
then constantly at 0V).
Check whether there is
27MHz signal output.
Check if there is 93MHz
signal output on R89.
Check the loaded circuit
Crystal oscillator Y1 and
peripheral components
are defected or eroded.
Check whether short-circuit
or bad solder on U7, U17
Check if short-circuit and bad
solder exist on Pin Y3
No
No
No
No
No
Yes Yes
Yes
Yes
Yes
Reconnect the component in
short-circuit
Check U3.
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