Sansui D 77R Service Manual

Page 1

SERVIC I G MAN I I A I OSPECIHCATIONS
Track .......... 4-Tnck (2-Channel Stereo)
sze Speed ....... 4.8 «cm/sec. (1-7/8 ips)

Heads [2-head configuration)

AUTO REVERSE CASSETTE DECK Rec/PB head . . . . HIGH-Es hard permalloy

Erase head ...... Double-gap HIGH-Es ferrite
Motor .......... Caustan: Elecrronically Controlled
DC Motor
Ausul -77 Reels: DC Motor
Wow and fluttel , . . . within 0.05 % WRMS
- Fast wind lime . . . approximately 30 seconds (060)
(Sllvef 8 BIaCK Model) Frequency response (420 VU recording/playback)

Normal Tape (LH) . 20 to 15,000 Hz
(301014,000 Hz 13 (13)
Chrome Tape . . . . 10 [0 17,000 Hz
(30t016,000 Hz :3 68)
Metal Tape .... 20 to 18,000 Hz
(30 to 17,000 Hz :3 dB)
Signal to noise ratio (Record/Playback)
Metal Tape [without Dolby Noise Reduction Effect)
. . . . . . . . . better than 58 dB (weighted)
(With Dolby Noise Reduction)
............ better than 68 438 (above 5 kHz)
Erasure (actor [Metal Tape)

........... more than 70 dB at 1,000 Hz
Input sensit ty and impedante (0 VU,1.0DO Hz)
MIC ......... 0.4 "IV/200K}. ~ 5 kn
LINE IN (REC) , . . 150 mVI47 kn

Output level (0 VU, 1,000 Hz)
LINE OUT (PLAY) 240 mV
Power requirements
Power voltage . . . . 120/220/240 V (50/60 Hz)
For U.S.A. 1nd Canada
........... 120 V {60 Hz)
Power consumption
............ 15 W
Dimensions ....... 430mm [16-15/16")W
118 mm (4-11I16") H
223 mm (8-13/16") D
Weight .......... 4.0 kg (8,81bs.) net
' 4,8 kg (10.6 lbs.) packed

Design and specifications subject to changes without
notice for improvements.

' The word "Dolby" is nmlernark of Dolby Laboratories.
This product is manufactured under the license from
Dolby Laboratories.

Smut-u}.
SANSUI ELECTRIC CO., LTD.

Page 2

1. BLOCK DIAGRAM

1-1. Recording Operation

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no TA7829?
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1-2. Playback Operation
DOLBV «use REDUCTION
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AMPS
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Page 15

8

A.

l)
2l
3)
4)

5

6)
7)
8)

B.
1)
2)

3)

C.
l)
2)
3)

D.
1)
2)

3)

E.
1)
2)

3)

4)
5)

F.
l)
2)
3)
4)
5)

G.
1)
2)

3

4)
5)

H
1)

2)
3)

. MAIN PARTS REPLACEMENT

Mechanism assembly

(See EXPLODED VIEW and Top View on Page l0)
Remove the bonnet and the bottom plate.
Cut off two vinyl bands for bundling wires.
Extract two connectors ® on the main circuit board F-3879.
Extract a connector G) on the mechanism control circuit board
F-3884.
Extract a connector (D on the mechanism control circuit board
F6818.
Remove four screws 19 fixing mechanism assembly.
Take off the counter belt from the reel hub.
Pull out the mechanism assembly from the rear panel side.

Reel motor assembly @
Pull out the mechanism assembly from the rear panel side.
Remove two screws ® fastening reel motor and idler gear arm
.

Pullout reel motor assembly from the back side.

Idler gear
Pull out the mechanism assembly from the rear panel side.
Remove the washer ® retaining the idler gear.
Remove the idler gear from idler gear arm.

Reel hub ® .Cushion (brake) {3)
Pull out the mechanism assembly from the rear panel slde.
Remove the thrust washer ® , reel cap ® , reel collar ®
and reel spring @ and extract the reel hub.
Extract the cushion (brake) from the brake slider®.

Capstan motor , flywheel ® . @
Pull out the mechanism assembly from the rear panel side.
Remove four screws ® and two screws ® fixing the cap-
stan motor mounting plate.
Remove one screw @ fixing connection terminal circuit board
@.
Remove three screws ® fixing the capstan motor.
Take out the flywheel from mechanism assembly.

Play cam gear ®
Perform the same manner as for the flywheel.
Remove two screws @, ® fixing play plunger solenoid @.
Remove the play plunger lever
Remove the CS type ring @ retaining the play cam gear.
Take ant the plain washer ® and extract the play cam gear.

AMPS cam gear @l
Perform the same manner as for the flywheel.
Remove the AMPS lock lever spring ® from the AMPS lock
lever @.
Remove the bush ® fasting AMPS lock lever and takeout the
AMPS lock lever.
Remove the CS type ring ® fasting AMPS cam gear.
Remove the plain washer ® and extract the AMPS cam gear.

Side panel L (R)
Remove four screws 9 fixing side panel L (R) from rear panel
side.
Remove bonnet and bottom plate.
Shift the position of the side panel L (R) 2cm in the arrow
direction (D and then pull it the arrow direction @ to remove
the side panel L (R). (See Fig. 8-1)

Side Panel

Display stage

1) Remove the side panel L and R. (See Replacement H)
2) Remove tension wire (See top view on page 10)
3) Remove the front panel assembly with mechanism assembly and

mechanism control circuit board F-3884.

4) Remove two screws ® fixing mechanism control circuit board

F6884. (See top view on page 10)

5) Remove the mechanism control circuit board F6884 from front

panel assembly.

6) Take off the tape counter belt from counter pulley. (See top

view on page 10)

7) Remove the tape counter holder from front panel (See Fig, 8-2)
8) Remove the control switch circuit board F-3880 from display

stage. (See Fig. 3-2)

9) Remove display stage from front panel assembly.

Fig. 8-2

Tape Counter
Holder

J. Front panel assembly

1) Perform the same manner as for the display stage.

2) Remove the mechanism assembly.

3) Remove the circuit board F3882, F-3883 from front panel

assembly (See top view on page 10)