Sony HCD-W550 / MHC-W550 / MHC-W770AV Service Manual ▷ View online
— 5 —
2-3.
MAIN BOARD, RESISTOR BOARD, FRONT PANEL ASSY REMOVAL
3
Screw
+BVTP 3
×
8
2
Front panel assy
6
Screw
+BVTP 3
×
8
1
Screw
+BVTP 3
×
8
4
Bracket (H/S)
5
Resistor board
7
Main board
• Tray (Slide) getting out procedure on the power supply is OFF
Rotate the BU CAM assembly in the direction of the arrow and pull out the slide.
Tray (Slide)
1
BU CAM assy
— 6 —
SECTION 3
ADJUSTMENTS
3-1.
MECHANICAL ADJUSTMENT
PRECAUTION
1.
Clean the following parts with a denatured-alcohol-moistened
swab:
swab:
record/playback head
pinch roller
erase head
rubber belts
capstan
idlers
2.
Demagnetize the record/playback head with a head
demagnetizer.
demagnetizer.
3.
Do not use a magnetized screwdriver for the adjustments.
4.
After the adjustments, apply suitable locking compound to the
parts adjusted.
parts adjusted.
5.
The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
supply voltage unless otherwise noted.
• Torque Measurement
• Tape Tension Measurement
3-2.
ELECTRICAL ADJUSTMENT
1.
The adjustment should be performed in the publication.
(Be sure to make playback adjustment at first.)
(Be sure to make playback adjustment at first.)
2.
The adjustment and measurement should be performed for both
L-CH and R-CH.
• Switch position
L-CH and R-CH.
• Switch position
DOLBY NR switch : OFF
FUNCTION button : OFF
EFFECT switch
FUNCTION button : OFF
EFFECT switch
: OFF
DBFB switch
: OFF
3.
Deck section electrical adjustments are made in test mode by
press key switch same time CD STOP DECK A STOP and
DECK B STOP button.
press key switch same time CD STOP DECK A STOP and
DECK B STOP button.
4.
Input point and output level measurement point.
•
Test Tape
0 dB=0.775V
Record/Playback Head Azimuth Adjustment
DECK A
DECK B
Procedure:
1.
1.
Forward Playback mode
Reverse Playback mode
Reverse Playback mode
Mode
Torque Meter
Meter Reading
Forward
CQ-102C
36 to 61g•cm
(0.50 – 0.84 oz•inch)
Forward
CQ-102C
2 to 6g•cm
Back Tension
(0.028 – 0.083 oz•inch)
Reverse
CQ-102RC
36 to 61g•cm
(0.50 – 0.84 oz•inch)
Reverse
CQ-102RC
2 to 6g•cm
Back Tension
(0.028 – 0.083 oz•inch)
FF, REW
CQ-201B
61 to 143g•cm
(0.85 – 1.99 oz•inch)
Mode
Tension Meter
Meter Reading
Forward
CQ-403A
more than 100 g (3.53 oz)
Reverse
CQ-403R
more than 100 g (3.53 oz)
DECK SECTION
Tape
Signal
Used for
P-4-A100
10 kHz, –10 dB
Head Azimuth Adjustment
P-4-L300
315 Hz, 0dB
Level Adjustment
WS-48B
3 kHz, 0dB
Tape Speed Adjustment
— 7 —
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 1 dB.
these levels do not match, turn the adjustment screw until both
of output levels match together within 1 dB.
3.
Playback Mode
4.
Change the playback mode and repeat the steps 1 to 3.
5.
After the adjustment, lock the adjustment screw with suitable
locking compound.
locking compound.
Adjustment Location:
— Record/playback head (Deck A and B) —
Tape Speed Adjustment
DECK A
DECK B
Note: Start the Tape Speed adjustment as below after setting to the
test mode.
Set to test mode. (Press key switch same time CD STOP
DECK A STOP and DECK B STOP button.)
Test mode off. (Power off.)
Set to test mode. (Press key switch same time CD STOP
DECK A STOP and DECK B STOP button.)
Test mode off. (Power off.)
Procedure:
• Perform high speed adjustment before normal speed adjustment.
• Perform high speed adjustment before normal speed adjustment.
Mode: Playback
* Continue to press HIGH SPEED DUBBING switch (S259) in
playback mode : High speed playback.
Frequency difference between the beginning and the end of the
tape should be within ± 3%.
Frequency difference between deck A and deck B the beginning
of the tape should be within 1.5 %.
tape should be within ± 3%.
Frequency difference between deck A and deck B the beginning
of the tape should be within 1.5 %.
Adjustment Location: AUDIO board (See page 8)
Sample Value of Wow and flutter
W.RMS (JIS) within 0.3%
(test tape: WS-48B)
(test tape: WS-48B)
Playback level Adjustment
DECK A
DECK B
Procedure:
— FWD playback Mode —
— FWD playback Mode —
Deck A is RV311 (L-CH) and RV411 (R-CH), Deck B is RV301
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
(L-CH) and RV401 (R-CH) so that adjustment within adjustment
level as follows.
Adjustment Level:
LINE OUT level : –8.2 to –7.2 dB (301.5 to 338.3 mV)
Level Difference between Channels : within 0.5 dB
Level Difference between Channels : within 0.5 dB
Confirm the OUTPUT level does not change in playback mode
while changing the mode from playback to stop several times.
while changing the mode from playback to stop several times.
Adjustment Location: AUDIO board (See page 8)
Speed
*High
Normal
Deck
A
B
A
B
Adjustment
RV652
RV652
RV651
RV651
Frequency counter
5,910 to 6,090 Hz
2,910 to 3,090 Hz
+
–
–
VTVM
set
test tape
P-4-L300
(315 Hz, 0 dB)
P-4-L300
(315 Hz, 0 dB)
Output level measurement point
(See page 6)
(See page 6)
— 8 —
Record Bias Adjustment
DECK B
Procedure:
1.
1.
Record mode
2.
Mode: Playback
3.
Confirm playback the signal recorded in step 1 become
adjustment level as follows.
adjustment level as follows.
4.
If these levels do not adjustment level, adjustment the RV341
(L-CH) and RV441 (R-CH) to repeat steps 1 and 4.
(L-CH) and RV441 (R-CH) to repeat steps 1 and 4.
Adjustment level: Playback output of 315 Hz to playback output
of 10 kHz: 0 ± 1.0 dB (0 ± 4.5mV).
Adjustment Location: AUDIO board
Record Level Adjustment DECK B
Procedure:
1.
Procedure:
1.
Record mode
2.
Playback mode
3.
Confirm playback the signal recorded in step 1 become
adjustment level as follows.
adjustment level as follows.
4.
If these levels do not adjustment level, adjustment the RV401
(L-CH) and RV451 (R-CH) to repeat steps 1 and 4.
(L-CH) and RV451 (R-CH) to repeat steps 1 and 4.
Adjustment Level:
OUTPUT level: –23.8 dB ± 1.0 dB (56.1 to 44.6 mV)
Adjustment Location: MAIN board
Adjustment Location :
[AUDIO BOARD]
[AUDIO BOARD]
— Component Side —
[MAIN BOARD]
— Component Side —
RV301 : Playback Level (Deck B L-CH)
RV401 : Palyback Level
(Deck B R-CH)
(Deck B R-CH)
RV651 : Tape Speed (Normal)
RV341 : Record Bias (L-CH)
RV441 : Record Bias (R-CH)
RV652 : Tape Speed
(Hight)
(Hight)
RV311 : Playback Level
(Deck A L-CH)
(Deck A L-CH)
RV411 : Playback Level (Deck A R-CH)
RV451 Record Level (R)
RV401 Record Level (L)
CNB108
attenuator
set
1) 315 Hz
2) 10 kHz
2) 10 kHz
69.0mV (–23.8dB) : STR-W550/W770AV
38.8mV (–26dB) : jig (PFJ-1)
38.8mV (–26dB) : jig (PFJ-1)
blank tape
CS-123
CS-123
AF OSC
Input point (See page 6)
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