Mechanical Adjustments; Electrical Adjustments; Test Mode; Tape Deck Section - Sony XR-C7220 Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

1. Clean the following parts with a denatured-alcohol-moistened
swab:
playback head pinch roller
rubber belt capstan
idlers
2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the power supply
voltage unless otherwise noted.
• Torque Measurement
Mode Torque Meter
Forward CQ-102C
Forward
CQ-102C
Back Tension
Reverse CQ-102RC
Reverse
CQ-102RC
Back Tension
FF, REW CQ-201B
• Tape Tension Measurement
Mode Tension Meter
Forward CQ-403A
Reverse CQ-403R

TEST MODE

This set have the test mode function. In the test mode, FM Auto
Scan/Stop Level and MW Auto Scan/Stop Level adjustments can
be performed easier than it in ordinary procedure.
<Set the Test Mode>
1. Set the "power select" switch (S501) is "A (ON)" position.
2. Turn ON the regulated power supply. (All LEDs on the set
3. Push the preset
4. Push the preset
5. Press the preset
6. Then the display indicates all lights, the test mode is set.
Meter Reading
30 – 65 g•cm
<Release the Test mode>
(0.42 – 0.90 oz•inch)
1. Push the
0.5 – 4.5g•cm
2. Return the "power select" switch (S501) to initially set posi-
(0.01 – 0.06 oz•inch)
30 – 65 g•cm
(0.42 – 0.90 oz•inch)
0.5 – 4.5g•cm
(0.01 – 0.06 oz•inch)
60 – 200 g•cm
(0.83 – 2.78 oz•inch)
Tape Speed Adjustment
Setting:
Meter Reading
more than 90 g
(more than 3.18 oz)
more than 90 g
(more than 3.18 oz)
Procedure:
1. Put the set into the FWD PB mode.
2. Adjust adjustment resistor for inside capstan motor so that the
Specification: Constant speed
Adjustment Location: See page 16.
– 13 –
SECTION 5

ELECTRICAL ADJUSTMENTS

lights up, and the clock is displayed.)
[OFF]
Note: Press the button, if the clock is not displayed.
[4]
button.
[5]
button.
[1]
button for more than two seconds.
[OFF]
button.
tion.
See the adjustment location from on page 15 for the
adjustment.

TAPE DECK SECTION

test tape
WS-48A
(3 kHz, 0 dB)
set
AUDIO OUT REAR jack (CNJ151)
reading on the speed checker or frequency counter becomes in
specification.
Speed checker
–1.5 to +2.5%
0 dB=0.775 V
speed checker
or
frequency counter
10 k Ω
– +
Frequency counter
2,955 to 3,075 Hz