Mechanical Adjustments; Record/Fast Forward/Rewind Torque Measurements; Record/Playback Head Azimuth Adjustment; Tape Speed Adjustment - Sharp MZ-700 Service Manual

Mechanical adjustments
RECORD/FAST FORWARDjREWIND torque measure-
ments
1. Set the torque measuring instrument on the cassette
tape recorder.
2. Torque value under each mode must be as follows:
Position
Torque measuring
Value
cassette
PLAYBACK TW-2111
30 '" 70gram·cm
FAST
TW-2231 60 '" 160gram·cm
FORWARD
REWIND TW-2231
60 '" 160gram·cm
Record/playback head azimuth adjustment
1. Set the instrument as shown in Fig. 4-2.
2. Playback the test tape (Teac's MTTlll, recorded with
3KHz signals).
3. Adjust the head azimuth adjusting screw so that the
reading on the digital voltmeter is at its maximum
value.
Cleaning of head
The head is critical for a proper performance of the tape
recorder. Dust on the head, capstan, pinch roller, etc.
impedes proper recording and playback. Open the cassette
holder, take out the tape, push down the PLAYBACK
pushbutton, then clean those components. If you can
see any oxide deposit, clean them using a cotton bud
damped with alcohol.
RECORD pushbutton can not be pushed in
The RECORD pushbutton can not be pushed in, if the
erasure protect tab of the cassette tape
is
broken. Forcible
depression of the button may result in machine failure.
17
Tape speed adjustment
1. Connect the wow-flutter measuring instrument to
:f#!,
pin of the CNW3001 connector.
2. Playback the test tape (UKOG-0119CSZZ, MTT-1l3
recorded with 8KHz signals). Use the middle part of the
tape for the test.
3. Adjust the
semi-fix~
resistor located on the Motor
Board so that the playback frequency should become
8000 ± 250Hz.
Test tape,
MTT-113
Pinch roller
Collector of transistor 03003 Digital
voltmeter
Figure 4-2.
Head