Adjustments; Mechanical Adjustments; Electrical Adjustments - Sony CFD-ZW755 Service Manual

4-1. MECHANICAL ADJUSTMENTS

PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
erase head
capstan
2. Demagnetize the record/playback head with a head demagne-
tizer. (Do not bring the head demagnetizer close to the erase
head.)
Do not use a magnetized screwdriver for the adjustments.
3. These measurement adjustment should be performed with the
rated power supply voltage (9 V) unless otherwise noted.
Torque Measurement
Mode Torque Meter
Forward
CQ-102C
Forward
back tension
Fast Forward
and CQ-201B
Rewind
Tape Tension Measurement
Mode Torque Meter
Forward CQ-403A
All manuals and user guides at all-guides.com
SECTION 4

ADJUSTMENTS

pinch roller
rubber belt
DECK A DECK B
Meter Reading
22.5 to 55 g • cm
(0.32 to 0.76 oz• inch)
2 to 5 g • cm
(0.03 – 0.069 oz• inch)
60 to 120 g • cm
(0.84 – 1.66 oz• inch)
DECK A DECK B
Meter Reading
more than 150 g
(more than 5.3 oz)
– 12 –

4-2. ELECTRICAL ADJUSTMENTS

TAPE SECTION 0 dB = 0.775V
Standard Output level
Outout terminal SP OUT
3.2 Ω
load impedance
output signal level 0.775V (0dB)
Test Tape
Type Signal
WS-48A 3kHz, 0 dB
Tape Speed Adjustment DECK A
Procedure :
test tape
WS-48A
(3kHz, 0 dB)
set
1. Playback WS-48A (tape center part) and adjust RV301 so that
the frequency counter reading becomes 3,000Hz.
Standard value : 2,985–3,015Hz
2. Playback WS-48A (tape top and end).
Check that frequency counter reading is within 1.5% of the read-
ing of step 1.
Adjustment Location :
[MAIN BOARD]
(Component side)
RV301 : Tape Speed Adjustment
PHONES OUT
32 Ω
0.25V (–10dB)
Used for
Tape Speed Adjustment
DECK B
digital frequency
counter
32 Ω
PHONES jack (J301)