No Signal Of Composit / S-Video Screen In Disc Play - Zenith DVR313 Series Service Manual

9. No Signal of COMPOSIT / S-VIDEO Screen in Disc Play

Q714 Collector :LOW?
YES
No signal after COMPOSIT?
YES
Check V. Buffer TR :Q716
power and ambient circuits.
YES
IC4003 -8 :HIGH ?
/RST 7104
YES
Check IC4003 -14,15
I2C CLK, DATA in resetting.
YES
IC4003 -19,20,36
Check clock signal input.
YES
Check
IC4002 =>IC4003
PD0 ~PD7 signal.
YES
Check IC1099 =>IC4002
VO_D0 ~VO_D15 signal.
NO IC704 -52 :HIGH ?
(VIDEO MUTE )
YES
Check IC712 power and
ambient circuits.
No signal after S-VIDEO:Y
signal?
Check V. Buffer TR :Q717
power and ambient circuits.
NO
Check IC2084-3,46 =>
IC2081-4,5 signal flow.
NO
Check IC2033-8,9 &
IC2001-8,9,10 signal flow.
NO
IC1099 =>IC4002 -37
VO_CLK signal check?
YES
NO
VO_CLK and IC4002 -22
Phase reversion?
YES
NO IC4002 power and
ambient circuits.
NO
NO
Check
3-8
Check V.MUTE TR (Q714,
Q715 ) ambient circuits.
No signal after S-VIDEO :C
signal?
Check R772, R724.
Check IC4009 -94 :VI_CLK0.
YES
Check X401 Clock generation.