Daewoo DR-C912B, Service Manual

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ADJUSTMENT OF THE TAPE TRANSPORT SECTION
A. ADJUSTMENT OF THE S/T GUIDE
ROLLER
A. Adjustment of the S/T GUIDE ROLLER
a. Check the Playing back with a T-120 TAPE.
b. Make sure that excessive tape wrinkle does not occure ateatch
S, T GUIDE ROLLER.
c. If tape wrinkle is observed at the S/T GUIDE ROLLER, turn the
guide roller screw until there is not tape wrinkle.
B. ADJUSTMENT OF THE AC HEAD
ASSÕY(TILT)
a. Play back a T-120 TAPE and check the running status of lower
side of GUIDE POST.
b. If there is any problem, Turn the AC HEAD TILT SCREW until
the running status improved. (Fig. 5.2)
C. ADJUSTMENT OF THE AC HEAD
HEIGHT(FIG. 5.3)
a. Paly back a T-120 TAPE..
b. Make sure that the gap between the lower end of TAPE and the
AC head is 0.25m.
c. If the measurement of the gap is different from the reference
value 0.25mm, turn the screw
!
,
#
until the desired gap
is obtained.
D. ADJUSTMENT OF THE AUDIO
AZIMUTH(FIG. 5.4)
a. Play back the ALIGNMENT TAPE
(DN2 : SP, NTSC,7KHz)
b. Check the AUDIO output with a AUDIO LEVEL METER.
c. Turn the AC HEAD AZIMUTH SCREW
@
until the maximum
AUDIO output(-9dBm ~ -3dBm)is obtained.
E. Adjustment of the X-POSITION(Fig. 5.4 5.5)
a. Connect the PATH ADJ. FIXTURE to the PT01 on the MAIN
CIRCUIT BOARD.
b. Play back the ALIGNMENT TAPE (DN2 : SP MONOSCOPE).
c. Connect the S/W pin and ENVE pin of the PATH ADJ. FIXTURE
with the SCOPE PROBE.
d. Insert the adjustment bar in the AC HEAD ADJUST hole
$
and
adjust the X-POSITION of the AC HEAD ASS‘Y until the ENVE
is maximum when the VR is on the CENTER.
¥ Three is the possibility that an another TRACKING CENTER can
be occur when the AC HEAD ASS‘Y turned completely in the
counterclockwise direction, Hence adjust the X-position with AC
HEAD ASS Y adhering closely to the right side until the maxi-
mum ENVE is obtained.
e. The adjustment of the X-POSITION finished, check if the
AUDIO LEVEL is degraded, then readjustment of the
AUDIO AZIMUTH is required.
FIg.5.2 Adjustment of the AC HEAD ASS Y
S/W PULSE TEST PIN PATH ADJ. FIXTURE
ENVELOPE TEST PIN PATH ADJ.FIXTURE
Measurement Equipment OSILLOSCOPE
VR CONTROL
PATH ADJ.FIXTURE
AC HEAD ADJUST HOLE ADJUSTMENT BAR
Test Point
Adjustment
FIg.5.3 Adjustment of AC HEAD Height
FIg.5.4 Adjustment of AUDIO AZIMUTH, X-POSITION