Sony TC-WR990 - Mechanical Adjustment Procedures; Mechanical Adjustment Precautions; Torque Measurement Methods; Electrical Adjustment Procedures

SECTION 4
ADJUSTMENTS
4-1. MECHANICAL ADJUSTMENTS
PRECAUTION
1.Clean the following parts with a denatured alcohol-
moistened swab :
record/playback/erase head pinch roller
rubber belts capstan
idlers
2.Demagnetize the record playback head with a head
demagnetizer.
(Head demagnetizer do not approach for the erase head.)
3.Do not use a magnetized screwdriver for the adjustment.
4. After the adjustments, apply suitable locking compound
to the parts adjusted.
5.The adjustments should be performed with the rated
power supply voltage unless otherwise noted.
Torque Measurement
Meter reading
30 to 65g +cm
CQ102C (0.42 to 0.9 02° inch)
DECK A:1 to 6g*cm
Forward
(0.014
to
0.08
oz»
inch)
CQ-102C
back tension DECK B:2 to 9g*cm
(0.03 to 0.12 oz inch)
30 to 65g+cm
Reverse 1 to 6g+cm
-102R'
back tension evens (0.014 to 0.08 02+ inch)
Forward, .
CQ201B 70 to 120g+cm
Reverse
(0.98 to 1.67 oz inch)
4-2. ELECTRICAL ADJUSTMENTS
PRECAUTION
1.The adjustment should be performed in the publication.
(Be sure to male playback adjustment at first.)
2.The adjustments and measurement should be performed
for both L-CH and R-CH.
* Switch position
DOLBY NR switch : OFF
DIR MODE switch areas
¢ Standard record position :
Deliver the standard input signal level to input jack
and set the REC LEVEL control to obtain the standard
output signal level as follows.
— Record Mode —
AF OSC
fc attenuator
o—o
Il ooo
o—o
VTVM
LINE IN LINE OUT
Standard Input Level
Input terminal LINE IN
input signal level 0.25V (- 10dB)
Standard Output Level
Output terminal LINE OUT
Test Tape
fae
P-4-A100 10kKHz, — 10dB Azimuth Adjustment
P-4-L300 315Hz, 0dB PB Level Adjustment
WS-48B 3kHz, 0dB Tape Speed Adjustment
OdB = 0.775V
Test Mode
Connect @ pin of IC801 to ground.
(place the IC801 pin 6 in ”L” status) on the MAIN board
with the power turned off, then turned the power on before
adjustment.
Executes high speed dubbing when the HIGH SPEED
(DUBBING) button is pressed during dubbing.
When pressing this button again, the normal speed dubbing
is restored.
After adjustment, break the short condition.
The DECK A and B can be adjusted in the same manner.
Record/Playback Head Azimuth Adjustment
Procedure:
1.Forward playback Mode
test tape
P-4-A100
(10kHz, ~ 10dB) VTYM
LINE OUT
2.Turn the adjustment screw for the maximum output
levels. If these levels do not match, turn the adjustment
screw until both of output levels match together within
1dB.
L-CH
peak output
level
RCH
peak
Screw
Position
R-CH peak angle
L-CH peak