Sanyo DC-DA90, Руководство по обслуживанию

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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.
1
2
3
4
4
MOTOR SPEED
ADJUSTMENT
d. Replacing the moto
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.
Measurement 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 - -
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.
OSCILLOSCOPE
+
TP1
(RF)
TP4
(VC)
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CD PLAYER ADJUSTMENTS