Philips PD7010, Руководство по обслуживанию, Страница: 17 / 36

5-7
No video picture, no sound.
Change EC42,L22,L21
No video picture,
no sound.
Check if the reset circuit consisting
of EC42,L22,L21,C88,C89,C90,R75 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 122MHz
signal output on R57.
Check the loaded circuit
Crystal oscillator XT1 and
peripheral components
are defected or eroded.
Check whether
short-circuit or bad
solder on U4, U8
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Reconnect the component in
short-circuit
Check U4.
27M waveform
SDRAM(R49 SDCLK) waveform
Check whether all the
voltages from the power
board to the decoder board
are normal.
CVBS(L27 point) waveform
Trouble shooting chart
Go
No