Servo-Reference Delay Mv (Pb); Tracking Control Check - Sony AV-3600 Service Manual

Signal
Source: Telecast signal
Equipment
Required:
(1)
Oscilloscope
(2)
TV
monitor
Procedure:
1.
Set
up
the E-to-E
mode
using a telecast signal.
2.
Connect the scope to
TP-403.
3.
Adjust
R413
to obtain the pulse
width (T) of
930
jusec as
shown
in Fig. 6-10.
4.
Confirm
that
the pulse
amplitude
is
6
±
1
V,
If
it
is
not,
and
the servo
system does not
stabilize,
check
MM401
and,
if
necessary, replace
it.
6-11.
SERVO-REFERENCE
DELAY
MV(PB)
The
servo-reference delay multivibrator adjusts the
precise
angular
position of the
heads with reference
to
the
playback video signal in
the
Playback
mode.
Test
Point/
Board:
Adjust for:
TP-403/SV
(Delayed 30
PG
pulse
output)
A
pulse
width of
1.9
msec. See
Fig. 6-11.
TP-403
(PB mode)
|<
1.9
ms
—
»|
scope
:
0.5
ms/cm
Fig.
6-
1 1.
Delay multivibrator
adjustmen
t
(PB
mode)
Adjustment/
Board:
R412/SV
(Lock Phase)
Signal
Source: Telecast signal
Equipment
Required:
(1)
Oscilloscope
(2)
TV
monitor
Procedure:
1.
Make
a
recording of a telecast
signal.
2.
Play
back the
tape.
3.
Connect
the
scope
to
TP-403.
4.
Adjust
R412
(PB
Lock
Phase) to produce
1.9
ms
pulse
width
as
shown
in Fig. 6-11.
6-12.
TRACKING CONTROL CHECK
This
test
checks the range of the variable tracking
control.
Test Point/
Board:
Check:
TP-408/SV
(Tracking
MV
output)
See
Fig.
6-12.
TP-408
L
1
1
1
1
i
i
!
U
rU
rl
^*
variable range
±6
ms
Fig.
6-12. Tracking control
check
Adjustments:
R007
(TRACKING
control)/Con-
trol
Panel
Signal Source: Telecast
signal
Equipment
Required:
(1)
Oscilloscope
(2)
Blank tape
(3)
TV
monitor
Procedure:
1
.
Make
a recording of
a telecast signal.
2.
Play
back
the
tape.
3.
Connect
the scope to
TP-408
Set the time base to 2
msec/cm.
4.
Pull
and
turn the
TRACKING
control
(RO07)
and confirm
that
the output
pulse
stiifts
±
6
msec
as
shown
in Fig. 6-12.
6-7