Sansui D 70 BW Service Manual

Page 1

SERVICE MANUAL

STEREO DOUBLE CASSETTE DECK

SANSUI D-7IIBW

CAUTION

1. Parts identified by the A symbol on the schematic
diagram and the parts list are critical for safety.
Use only replacement parts that have critical charac-
teristics recommended by the manufacturer.

2. Make leakage-current or resistance measurements
to determine that exposed parts are acceptably in-
sulated from the supply circuit before returning the
appliance to the customer.

Satmu'.

SANSUI ELECTRIC CO., LTD.

D-7OBW

ISPECIFICATIONS

Track format .. MracklZ-channel system

Tape speed... .. 4.8 cm/sec.

Heads
Rec/play head. .. HIGH»Bs hard permalloy
Play head HlGH-Bs hard permalloy
Erase head Double-gap HICHvBs ferrite

Motor .......... ., Electronically controlled DC

motoer (2 spead)
Reels: DC Motoer
Wow/flutter .................... 0.06% max lWRMS)
Fast fomarding (rewinding) lime
.................................. Approx. 90 sec.
(for 060 tape)
Frequency response {-20 VU recording/playback)

Normal tape (LH) ....... 20 to 15,000 Hz

(30 to 14,000 Hze} dB)
Chrome Tape ............. 20 to 16,000 Hz

(30 to 15,000 H123 dB)
Metal Tape ................. 20 to 17,000 Hz

(30 to 16,000 H213 dB)

Erasure rate (metal tape)
.................................. 70 d8 min (1 kHz)
Recording as frequency

LINE lN (REC),
Signal to noise ra
Metal Tape (wtthout Dolby Noise Reduction)
DOLBY NR OFF ..

DOLBY NR ON.
Power requirements
Power voltage ............. 110/120/220/240V
(50/60 Hz)
For U.S.A. and Canada
. . 120V (60 HZ)
20 watts

Dimensions ............... .. 430 mm (16-15/16') W
112 mm (4~7/16') H
. 221 mm (8-3/4'} D
Weight ............................ 4.0 kg (8.6 lbs.) net

- Deslp and wedllulions whim lo thanla without notiu rat im-
WORM.

- Due In local hm and regulations, lhil unit told in mm IRIS m not
equipped with variable mung neledon

Page 2

D-7OBW

CAUTION
1. The symbols, UL, CSA, SA, BS, UK, EU, AS and XX (EXPORT) on
the parts list and the schematic diagram mean followings respectively.

UL ....................... Manufactured for U.S.A market.
(Underwriters Laboratories approved model.)

CSA.... Manufactured for Canadian market.

8A.... Manufactured for South African market.
BS, UK ............... Manufactured for United Kingdom market.
EU Manufactured for European market.

AS ....................... Manufactured for Australian market.

XX (EXPORT) ..... Standard Version.
NON MARK ........ Common Parts.

2. Some printed circuit boards are not supplied assembled.
To separate these in this service manual, the stock numbers are not
indicated for these boards. However, stock numbers for individual
parts are indicated.

3. Since some of capacitors and resistors are omitted from parts lists
in this service manual, refer to the Common Parts List for capacitors
& resistors, which was issued on February 1983.

4. Abbreviations in this service manual are as follows.

oAbbreviations List

C.R. : Carbon Resistor ES. 2 Bi-Polar Electrolytic

S.R. : Solid Resistor Capacitor

W.R. : Wire Wound Resistor E.B.L. : Low Leakage Bi~Polar

M.R. : Metal Film Resistor Electrolytic Capacitor

F.R. : Fusing Resistor Ta.C. : Tantalum Capacitor

N.I.R. : Non-lnflammable Resistor F.C. : Film Capacitor

RA. : Resistor Array M.P. : Metallized Paper Capacitor

C.C. : Ceramic Capacitor P.C. : Polystyrene Capacitor

C.T. : Ceramic Capacitor, C.A. : Capacitor Array
Temperature Compensation V.R. : Variable Resistor

E.C. : Electrolytic Capacitor SW. : Switch

E.L. : Low Leakage Electrolytic Chip R. : Chip Resistor

Capacitor Chip C. : Chip Capacitor

Page 5

3. ADJUSTMENTS

3-1.Tape Speed Adjustment f-)

. Adjust the tape speed of b-side as fast as a-side. Fig. 3-2
Note: 1. Use Sansui Test Tape, SCT-SSK.
(3 kHz signals are recorded on the tape).
2. Connections are shown in Fig. 3-1.

< F4729 >

Fig. 3-1 cassette nscx FAEOUENCV counter!
w ' " DUDE]
~'-_l L

1) Tape Speed Adjustment (NORMAL SPEEQ)

STEP SUBIEG gfifflr SETHNG ADJUSTMENT ADIUST FOR REMAIKS
I. A Side Mecha. LINE OUT Playback the TEST Turn semi-variable resistor - +30 Use small screw driver.
(NORMAL) Frequency TAPE SCT-SJK. (tVRI) of A Side Media. as SOOOHZ 0 Hz
counter A Side Mecha. Fig. 3-2. '
2, B Side Media. Playback the TEST Turn semi-variable resistor +30
(NORMAL) TAPE SCT-SZK. (tVRl) 0f 5 Side Mecha. as SOLDHZ_0 HZ
8 Side Mecha. Fig. 3-2.

2) Tape Speed Adjustment (HIGH SPEED)

Notezt .Before this adjustment, regulate "3-I. Tape Speed 2. Short between the R3 on F-4729 & CND. \
Adjustment (NORMAL SPEED)". (See Fig. 3-2)
srer SUBJECT 635$: strrth Autusmem ADIUST FOR REMARKS

I. A Side Mecha. LINE OUT Pla back the TEST Turn semi-variable resistor +60 Use small screw driver,

(HIGH) Frequency TA E SCT-SJK. (tVRZ) of A Side Mecha. as 6000Hz Hz

counter A Side Mecha. Fig. 3-2. 0

2. B Side Mecha. Playback the TEST Turn semi-variable resistor +60

(HIGH) TAPE SCT-SJK. (will) at 8 Side Mecha. as 600(2sz_0 Hz

B Side Mecha. Fig. 3-2. 0

3-2. Playback Adjustment

Note: I. Before this adjustment, clean REC/RB. head surface. 3. Set the Dolby NR switch to be OFF.
2. For this adjustment, use Sansui Test Tape, SCT-FIOK, 4. Connections are shown in Fig. 3-3.
and SCF-L400. .
3' 33 VTVM oscruoscow: 3 3" R c PB Hm

CASSEYT E DECK

n n A A
m: j~ - - _i~ out .-.\L.v >1
1) a-Side Mecha. Adjustment m" """W' MW 5""
MEASURE
STEP SUBJECT OUTPUT SETTING ADIUSTMENT ADJUST FOR REMARKS
1. RECIPJi. Head LINE OUT Playback the TEST Adjust the azimuth MAX. Output Refer to remavement of Lid Assy on Page
Adj. VTVM and Scope TAPE SCT-FIOK adjusting screw in Fig. 34. both channels 7.
on FWD and After this adjustment. lock the screw with
REV PLAY paint.
2. Playback Lev,e| Between across Pla back the TEST Adjust each vVRSOI lL-CH IOngZdB See Fig. 3-6 on Page 5.
Pre Adi. VR509 (LCH and TA SCT-Lm and R-CH, F-5397l
R-CH, F-5397)
VTVM and Scape
3. Playback Level LINE OUT Playback the TEST Adjust each vaI (L-CH lzomvgzdfl See Top Wew on Page 16.
Ad]. VTVM and Scope TAPE SCT-L400 and R-ch. F5336)
2) b-Side Mecha. Adjustment
MEASURE
STEP SUBJECT OUTPUT SETTING ADIUSTMENT ADIUST FOR REMARKS
I. REC/RB. Head LINE OUT Playback the TEST Adjust the azimuth MAX. Output Refer to removemertt at Lid Ass'y on Page
Adj. VTVM and Scope TAPE SCT-FTOK adjusting screw in Fig. 34. both channels 7. )
on FWD and After this adjustment. lock the screw with \
REV PLAY paint.
1. Playback Level LINE OUT Plagiback the TEST Adjust each vVRI lL-CH 320mV*2dB See Top View on Page I6.
Adj. VTVM and Scope TA SCT-UOO and R-CH, F-SlZdl