Sony HCD-RG190 / HCD-RG290 / MHC-RG190 / MHC-RG290 Service Manual ▷ View online
17
HCD-RG190/RG290
SECTION 5
MECHANICAL ADJUSTMENTS
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
pinch roller
erase head
rubber belts
capstan
idlers
2. Demagnetize the record/playback head with a head
demagnetizer. (Do not bring the head magnetizer close to the
erase head.)
erase head.)
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, appiy suitable locking compound to
4. After the adjustments, appiy suitable locking compound to
the parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
TORQUE MEASUREMENT
Mode
Torque Meter
Meter Reading
2.6 – 6.9 mN
⋅
m
FWD
CQ-102C
(30 – 70 g
⋅
cm)
(0.41 – 0.97 oz
⋅
inch)
FWD
0.15 – 0.59 mN
⋅
m
Back Tension
CQ-102C
(1.5 – 6.0 g
⋅
cm)
(0.021 – 0.083 oz
⋅
inch)
5.4 – 16.7 mN
⋅
m
FF/REW
CQ-201B
55 – 170 g
⋅
cm)
0.76 – 2.35 oz
⋅
inch)
TAPE TENSION MEASUREMENT
Mode
Tension Meter
Meter Reading
FWD
CQ-403A
more than 100 g
(more than 3.53 oz)
18
HCD-RG190/RG290
4. After the adjustments, apply suitable locking compound to
the pats adjusted.
Adjustment Location: Playback Head (DECK-A)
Record/Playback/Erase Head (DECK-A)
1. Demagnetize the record/playback head with a head
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
3. After the adjustments, apply suitable locking compound to the
parts adjust.
TEST TAPE
Tape
Signal
Used for
P-4-A063
6.3 kHz, -10 dB
Azimuth Adjustment
RECORD/PLAYBACK HEAD AZIMUTH ADJUSTMENT
Note 1:
Remove the mecha deck before this adjustment.
(Refer to Section 3. DISASSEMBLY (See page 6))
(Refer to Section 3. DISASSEMBLY (See page 6))
Note 2:
Perform this adjustment for both decks.
Procedure:
1. Mode: Playback
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw
so that outputs match within 1dB of peak.
so that outputs match within 1dB of peak.
3. Mode: Playback
set
test tape
P-4-A063
(6.3 kHz, –10 dB)
P-4-A063
(6.3 kHz, –10 dB)
oscilloscope
V
H
waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
good
wrong
MIC. AUX. HP board
PHONES jack
(J701)
PHONES jack
(J701)
Screw
position
position
L-CH
peak
peak
within
1dB
1dB
Output
level
level
L-CH
peak
peak
R-CH
peak
peak
within
1dB
1dB
Screw
position
position
R-CH
peak
peak
SECTION 6
ELECTRICAL ADJUSTMENTS
0 dB=0.775 V
DECK SECTION
set
MIC. AUX. HP board
PHONES jack
(J701)
PHONES jack
(J701)
+
–
–
level meter
test tape
P-4-A063
(6.3 kHz, –10 dB)
P-4-A063
(6.3 kHz, –10 dB)
19
HCD-RG190/RG290
CD SECTION
Note:
1.
CD Block is basically constructed to operate without adjustment.
2.
Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3.
Use an oscilloscope with more than 10 M
Ω
impedance.
4.
Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
signal level is low than specified value with the following checks.
5.
Check the focus bias check when optical pick-up block is replaced.
•
Abbreviation
MX: Mexican model
MX: Mexican model
FOCUS BIAS CHECK
Procedure :
1. Connect oscilloscope to TP (RFACI) and TP (VC) on the CD
board (Except RG290: MX) or BD board (RG290: MX).
2. Press the
I/
1
button to turn the power on, and press
the
A
button to open the CD disc table.
3. Set disc (YEDS-18) on the tray and press the
7
button to
playback.
4. Confirm that oscilloscope waveform is as shown in the figure
below. (eye pattern)
A good eye pattern means that the diamond shape (
A good eye pattern means that the diamond shape (
◊
) in the
center of the waveform can be clearly distinguished.
Connecting Location:
+
–
–
CD board (Except RG290: MX)
BD board (RG290: MX)
BD board (RG290: MX)
TP (RFACI)
TP (VC)
TP (VC)
oscilloscope
(DC range)
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level:
0.9
0.9
±
0.4 Vp-p
TP
(VC)
TP
(RFACI)
IC201
– CD Board (Conductor Side) (Except RG290: MX) –
TP
(VC)
TP
(RFACI)
IC201
– BD Board (Conductor Side) (RG290: MX) –
20
HCD-RG190/RG290
MEMO
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