Sony TC-RX77 - Section 3 Adjustments; Mechanical Adjustments; Electrical Adjustments

TC-RX77/RX77ES |
SECTION 3
ADJUSTMENTS
3-1, MECHANICAL ADJUSTMENTS
PRECAUTION
1, Clean the following parts with a denatured-
alcohol-moistened swab :
record/playback head pinch roller
erase head rubber belts
capstan idler
2, Demagnetize the record/playback head with a head
demagnetizer,
3. Do not use a magnetized screwdriver for the ad-
justments,
4, After the adjustments, apply suitable locking compound
to the parts adjusted,
TORQUE MEASUREMENT
CQ-102C [80 - 60g cm (0.42 — 0.8302 inch)
F
WD -
WD
CQ- 102C 1—5g+cm (0.014 — 0.0690z + inch)
Back tention
REV =
TREV.——sT«Ss CQ 102RC_—« [30 - 60g +cm (0.42 — 0.830z* inch)
REV
. CQ~ 102RC
Back tention
FF, REW CQ~-201B 65 —90*cm (0.9 — 1.2502 « inch)
1—5gecm (0.014 — 0,0690z + inch)
3-2, ELECTRICAL ADJUSTMENT
Note: The adjustment should be performed in the order given
in the service manual. As a rule, adjustments about
playback should be performed before those about recording.
The adjustments should be performed for both L-
CH and R-CH,
* Switches and controls should be set as follows unless
otherwise specified,
DOLBY NR switch : OFF
DIRECTION switch oe
¢ Standard Record:
Deliver the standard input signal level to the input jack
and set the REC LEVEL control to obtain the standard
output signal level,
—Record Mode—
AF OSC
VTVM
me) 10k Q
O Attenuator
e—_—
oO O
I] ooo |
ee |
LINE. IN LINE OUT
Standard Input Level
input terminal LINE IN
Standard Output Level
Test Tape
P-4-A100 10kHz, —10dB Azimuth Adjustment
P-4-L300 315Hz, 0dB PB Level Adjustment
3kHz, 0dB Tape Speed Adjustment
Test Mode
1, Put the set into the test mode by shorting test point TP801
(TEST) of the main bord during the set is turned off.
2. Remove the short after the Electrical Adjustment is completed.
Record Playback Head Azimuth Adjustment
Procedure :
1, Mode: FWD playback
Test tape
P-4-A100
(LOkHz, —10dB) VTVM
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
k
a within
1dB
R-CH
peak
Screw
position