Sony HST-471 User manual

HST-471
AEP Model
UK Model
E Model
Australian Model
SERVICE MANUAL
CASSETTE DECK RECEIVER
MICROFILM
Tape deck Model Name Using Similar Mechanism HCD-GR8/RX90
Section Tape Transport Mechanism Type TCM-220WR2
SPECIFICATIONS
Manufactured under license from Dolby
Laboratories Licensing Corporation.
“DOLBY” and the double-D symbol aare
trademarks of Dolby Laboratories Licensing
Corporation.
— Continued on next page —
This set is the tunerdeck
and amplifier section
in SEN-R4720/R5750.

— 2 —
TABLE OF CONTENTS
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK !OR DOTTED LINEWITH
MARK !ON THE SCHEMATIC DIAGRAMS AND INTHE PARTS
LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS
APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS
PUBLISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
MODEL IDENTFICATION
— Model Number Label —
AEP, UK : AC 220-230V ~ 50/60Hz 240W
Australian : AC 240V ~ 50Hz 240W
E, Singapore : AC 110-120, 220-240V selectable ~ 50/60Hz 240W
MODEL IDENTIFICATION
MODEL NO. HST-471
CASSETTE DECK RECEIVER
1. GENERAL
• Tuner/Amp Section ···································································· 3
• Deck Section ·············································································· 3
2. MECHANICAL ADJUSTMENTS ·························· 4
3. ELECTRICAL ADJUSTMENTS ···························· 4
4. DIAGRAMS
4-1. Circuit Boards Location ····················································· 8
4-2. Block Diagram ··································································· 9
4-3. Schematic Diagram — Deck Section — ·························· 12
4-4. Printed Wiring Board — Deck Section — ······················· 15
4-5. Printed Wiring Board — Main Section — ······················· 17
4-6. Schematic Diagram — Main Section — ·························· 19
4-7. Schematic Diagram — Display Section — ······················ 23
4-8. Printed Wiring Board — Display Section — ··················· 27
4-9. Printed Wiring Board — Power Section — ····················· 30
4-10. Schematic Diagram — Power Section — ························ 33
4-11. IC Block Diagrams ··························································· 36
4-12. IC Pin Function ································································ 38
5. REPAIR PARTS LIST
5-1. Main Section····································································· 40
5-2. Front Panel Section ·························································· 41
5-3. Tape Mechanism Deck Section-1
(TCM-220WR2) ······························································· 42
5-4. Tapa Mechanism Deck Section-2
(TCM-220WR2) ······························································· 43
6. ELECTRICAL PARTS LIST ··································· 44

— 3 —
SECTION 1
GENERAL
•TUNER/AMP SECTION
110 KEY
2MEMORY
3TUNING (–/+)
4BAND
5MEMORY SCAN
6STEREO/MONO
7POWER
8CENTER MODE
9SURROUND MODE (DOLBY/HALL/SIMULATED)
!º CONTROL MODE (–/+)
!¡ CONTROL MODE
(TONE/CENTER/REAR/WOOFER)
!™ MASTER VOLUME
!£ WOOFER ON/OFF
!¢ VIDEO 1/VIDEO 2/TAPE/CD/TUNER/PHONO
!∞ SOUND FIELD
(1 ROCK/2 POPS/3 CLASSIC/4 MOVIE/5 GAME)
• DECK SECTION
!§ 0(DECK A)
!¶ )(DECK A)
!• p(DECK A)
!ª ª(DECK A)
@º ·(DECK A)
@¡ DIRECTION (DECK B)
@™ DOLBY NR (DECK B)
@£ DUBBING SPEED (HIGH/NORMAL) (DECK B)
@¢ REC (PAUSE/REC MUTE/REC) (DECK B)
@∞ 0(DECK B)
@§ p(DECK B)
@¶ ª(DECK B)
@• ·(DECK B)
@ª )(DECK B)

— 4 —
SECTION 2
MECHANICAL ADJUSTMENTS SECTION 3 ELECTRICAL 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.
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 rated power
supply voltage unless otherwise noted.
•Torque Measurement
•TapeTension Measurement
DECK SECTION 0 dB=0.775V
1. Demagnetize the record/playback head with a head
demagnetizer. (Do not bring the head demagnetizer close to
the erase head.)
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjust.
4. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in this
servicemanual. (Asageneral rule,playback circuitadjustment
should be completed before performing recording circuit
adjustment.)
6. The adjustments should be performed for both L-CH and R-
ch.
7. Switchesand controlsshould beset asfollows unlessotherwise
specified.
8. Set to test mode. (Press key switch same time
SPECTRUM ANALYZER ENTER/NEXT and
EFFECT ON/OFF button.)
• Test Tape
Record/Playback Head Azimuth Adjustment
DECK A DECK B
Note : Perform this adjustments for both decks. Remove the covers
of cassette holders.
Procedure:
1. Mode: Playback (FWD)
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 (0.026 – 0.082 oz•inch)
Reverse CQ-102RC 36 to 61g•cm
(0.50 – 0.84 oz•inch)
Reverse CQ-102RC 2 to 6g•cm
Back Tension (0.026 – 0.082 oz•inch)
FF, REW CQ-201B 61 to 143g•cm
(0.85 – 1.98 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)
Tape Signal Used for
P-4-A100 10 kHz, –10 dB Azimuth Adjustment
WS-48B 3 kHz, 0dB Tape Speed Adjustment
P-4-L300 315 Hz, 0dB Level Adjustment
set
rear panel
VIDEO1
AUDIO OUT connector
(L: L-CH)
(R: R-CH)
+
–
level meter
test tape
P-4-A100
(10 kHz, –10 dB)

— 5 —
2. Turn the adjustment screw and checkoutput 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.
3. Mode: Playback (FWD)
4. Repeat steps 1 to 3 in playback (REV) mode.
5. After the adjustments, apply suitable locking compound to the
pats adjusted.
Adjustment Location: Record/Playback Head (Deck A and B)
and main board.
reverse
forward
Tape Speed Adjustment DECK A
Note: Start the Tape Speed adjustment as below after setting to the
test mode.
Procedure:
Mode: Playback (FWD)
1. Insert the WS-48B into the deck A and the blank tape into the
deck B.
2. Press the REC button and ·button on the deck B. Then
the deck B is at recording mode.
3. Set the deckA to playback mode.
4. Press the DUBBING SPEED HIGH button in playback mode.
Then at HIGH speed mode.
5. Adjust RV652 on the AUDIO board do that frequency counter
reads 6,000 ± 90 Hz.
6. Press the DUBBING SPEED NORMAL button in playback
mode.
Then at NORMAL speed mode.
7. Adjust RV651 on theAUDIO board so that frequency counter
reads 3,000 ± 90Hz.
8. FrequencydifferencebetweendeckAanddeck Bthe beginning
of the tape should be within ± 1.5 %.
Adjustment Location: AUDIO board
Sample Value of Wow and flutter
W.RMS (JIS) within 0.3%
(test tape: WS-48B)
Playback level Adjustment DECK A DECK B
Procedure:
Mode: Playback (FWD)
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.
Adjustment Level:
VIDEO1 AUDIO OUT PB level: 301.5 to 338.3 mV (–8.2 to
–7.2 dB) level difference between the channels: within ± 0.5
dB
Adjustment Location: AUDIO and main boards
Screw
position
L-CH
peak
within
1dB
output
level
L-CH
peak R-CH
peak
within
1dB
Screw
position
R-CH
peak
set
test tape
P-4-A100
(10kHz, –10dB) oscilloscope
L
R
V
waveform of oscilloscope
in phase 45 ° 90 ° 135 ° 180 °
good wrong
rear panel
VIDEO1
AUDIO OUT connector
H
+
–
set
test tape
WS-48B
(3 kHz, 0 dB) frequency counter
rear panel
VIDEO1
AUDIO OUT connector
(L: L-CH)
(R: R-CH)
+
–
level mete
r
set
test tape
P-4-L300
(315 Hz, 0 dB) rear panel
VIDEO1
AUDIO OUT connector
(L: L-CH)
(
R: R-CH
)

— 6 —
Record bias Current Adjustment DECK B
Procedure:
1. Mode: Record
2. Mode: Playback
Confirm playback the signal recorded in step 1 become adjustable
limits as follows.
If these levels do not adjustable limits, adjustment the RV341 (L-
CH) and RV441 (R-CH) on the AUDIO board to repeat steps 1 and 2.
Adjustable limits: Playback output of 315 Hz to playback output
of 10 kHz: ±0.5 dB
Adjustment Location: AUDIO and main boards
Record Level Adjustment DECK B
Procedure:
1. Mode: Record
2. Mode: Playback
Confirm playback the signal recorded in step 1 become adjustable
limits as follows.
If these levels do not adjustable limits, adjustment the RV511 (L-
CH) and RV521 (R-CH) on the main board to repeat steps 1 and 2.
Adjustable limits:
CN207 PB level: 47.3 to 53.1 mV (–24.3 to –23.3 dB)
Adjustment Location: main board
[MAIN BOARD] (Component Side)
[AUDIO BOARD] (Conductor Side)
attenuator
set
CD IN connector (L: L-CH)
(R: R-CH)
1) 315 Hz
2) 10 kHz 50 mV (–23.8 dB)



600 Ω
blank tape
CS-123
AF OSC
rear panel
+
–
set
recorded
portion level mete
r
rear panel
VIDEO1
AUDIO OUT connector
(L: L-CH)
(
R: R-CH
)
set
CD IN connector (L: L-CH)
(R: R-CH)
315 Hz, 50 mV (–23.8 dB) blank tape
CS-123
600
Ω
attenuator
AF OSC
rear panel
+
–
set
recorded
portion level mete
r
rear panel
VIDEO1
AUDIO OUT connector
(L: L-CH)
(
R: R-CH
)
IC303
IC501
J301
J302
RV511
RV521
CN317
CN321
CN361 CN363
RV301
RV401 L
R
PB LEVEL
— DECK B —
— DECK A —
(NORMAL)
RV651 (HIGH) RV652
PB
LEVEL
RV311
RV411
R
L
TAPE SPEED
RL
RECORD
BAIS
RV441 RV341

— 7 —

— 8 —
SECTION 4
DIAGRAMS
4-1. CIRCUIT BOARDS LOCATION
DISPLAY BOARD
TEN KEY BOARD
SUB HP BOARD
HP BAORD
SECONDARY BOARD
DECK A BOARD
LEAF SWITCH BOARD
AUDIO BOARD
DECK B BOARD WOOFER BOARD
POWER BOARD
MAIN BOARD
TUNER UNIT
PRIMARY BOARD
AC BOARD

HST-471
4-2. BLOCK DIAGRAM
— 9 — — 10 — — 11 —
• Signal path
: TUNER/AUDIO
: PB (DECK A)
: PB (DECK B)
: REC (DECK B)
: CD
: VIDEO-1 AUDIO
: VIDEO-2 AUDIO