Panasonic Omnivision PV-9661 - Page 358

CM Advance Section
Record any broadcast including commercial over 30 seconds. Then, as recording continues, proceed with all troubleshooting
of CM Advance Circuit.
HOW TO CONFIRM IF CM ADVANCE CIRCUIT IS WORKING.
START
Confirm if control pulse at Pin 5 of P1541 on A/C Head unit changes
as shown in Fig.1 when the black portion(No video & No audio) at
both the beginning and end of a commercial appears on TV.
CM Advance circuit works OK.
OK
NG
Perform the "TROUBLESHOOTING OF CM ADVANCE."
Control Pulse at Pin 5 of P1541 on AC Head Unit
approx. 1.5V
approx. 4V
33.3msec
(DUTY)
60% 40%
Fig.1
approx.4V
approx. 1.5V
(DUTY)
33.3msec
72.5%27.5%
TROUBLESHOOTING OF CM ADVANCE
Confirmation of Audio signal
Confirm if the signal at TP3801
becomes LOW when the black
portion (no audio) at both the
beginning and end of a
commercial appears on TV.
Confirm if the signal at Pin 43 of
IC6001 becomes LOW when the
black portion (no video) at both
the beginning and end of a
commercial appears on TV.
Confirm if the signal at TP3802
becomes LOW when the black
portion (no video) at both the
beginning and end of a
commercial appears on TV.
Check signal line between Pin 44
of IC6001 and Pin 11 of IC3801.
Confirm if the signal at Pin 44 of
IC6001 becomes LOW when the
black portion (no audio) at both
he beginning and end of a
commercial appears on TV.
Check IC3801 and parts
surrounding Pin 3, 4, 5, 7 and 8
of IC3801.Replace if necessary.
Confirmation of Video signal
Check IC3801 and parts
surrounding Pin 28 and 30 of
IC3801.Replace if necessary.
Check signal line between Pin 43
of IC6001 and Pin 25 of IC3801.
Check IC6001.
Replace if necessary.
Is E/V Mask pulse at TP3803
correct as shown in Fig.2?
Is there the video signal at Pin
33 of IC3801?
Is E/V Mask pulse at Pin 2 of
IC6001 correct as shown in
Fig.2?
Check signal line between
Pin2 of IC6001 and Pin 13 of
IC3801.
Check IC3801 and parts
surrounding Pin 21, 22, 31, 32,
and 33 of IC3801.Replace if
necessary.
Check signal line between Pin
25 of IC3001 and Pin 33 of
IC3801.
NG
NG
NGNG
NG
NG
NG
OK
OK
OK
OK
OK
OK
OK
Confirmation of E/V Mask pulse
approx.5V
approx.0V
approx.5V
approx.0V
TP3805
(V pulse)
TP3803
/Pin 2 of IC6001
(E/V Mask pulse)
approx. 5msec approx. 12.5msec
V rate
Fig.2