Tape Adjustments - Sanyo DC-DA90 Service Manual

CD PLAYER ADJUSTMENTS
(2) Checking the "eye" pattern
1. Switch "ON" the POWER.
2. Connect an oscilloscope to TP1 (RF) and TP4 (VC).
3. Load the test disc.
4. Press the PLAY button.
5. Check to be sure that the "eye" pattern is at
the center of waveform and that the diamond
shape is clearly defined.
6. Press the STOP button.
7. Turn off the POWER switch.

TAPE ADJUSTMENTS

a. Replacing the head
1. After replacement, demagnetize the heads by using
a degausser.
2. Be sure to clean the heads before attempting to make
any adjustments.
3. Be sure both channels (1 and 2) are the same level.
(Using a dual-channels oscilloscope).
4. All wiring should be returned to the original position
after work is completed.
b. Adjusting head azimuth
1. Load a test tape (VTT-738, etc. :10kHz) for
azimuth adjustment.
2. Press the PLAY button.
3. Use a cross-tip screwdriver to turn the screw for
normal azimuth adjustment so that the left and right
outputs are maximized at the same phase during
normal playback.
4. Press the STOP button.
d.
c.
R / P HEAD
RED WHITE
YELLOW EARTH
e. Checking the mechanism torques
Measurement
Cassette for
measurement F.FWD/REW : TW-2231
F.FWD/REW
- 3 -
+
TP1
(RF)
OSCILLOSCOPE
-
TP4
(VC)
a
Replacing the moto
Adjusting motor speed
1. Insert the test tape (MTT-111 or etc. 3,000 Hz).
2. Press the PLAY button.
3. Use a flat-tip screwdriver to turn the SVR to adjust so
that the frequency counter becomes 3,000 Hz.
4. Press the STOP button.
MOTOR SPEED
ADJUSTMENT
1
4
• Clean the head, capstan and pinch roller before making
any measurement.
Take-up torque
PLAY : TW-2111A
PLAY 30 ~ 70gr.cm
55 gr or more
OPENING EXPANDED
b
3
2
4
Back tension Tape tension
PLAY : TW-2111A Drive-power cassette
TW-2412
1.0 ~ 6.0gr.cm 80 gr or more
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