Sanyo DC-DA70, Service Manual

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OPENING EXPANDED
b
a
(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.
CD PLAYER ADJUSTMENTS
OSCILLOSCOPE
+
TP1
(RF)
TP4
(VC)
-
TAPE ADJUSTMENTS
R / P HEAD
RED WHITE
YELLOW EARTH
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. Replacing the motor
1
2
3
4
4
MOTOR SPEED
ADJUSTMENT
c. 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.
e. Checking the mechanism torques
• Clean the head, capstan and pinch roller before making any
measurement.
Measureent Take-up torque Back tension Tape tension
Cassette for PLAY : TW-2111A PLAY : TW-2111A Drive-power cassette
measurement F.FWD/REW : TW-2231 TW-2412
PLAY 30 ~ 70gr.cm 1.0 ~ 6.0gr.cm 80 gr or more
F.FWD/REW 55 gr or more - -