Sansui AV 77 Service Manual

Page 1

AV-77

SERV CE MANUAL 'SPECIFICATIONS

Video section
VIDEO INPUT sensitivity/Impedance
...................... I eI-llmpieg Vp-p/75 ohms
VIDEO OUTPUT m a
AUDIO VIDEO PROCESSOR " 1 0 331,75 ohms
SignaI- to-noise ratio (video signal)

VCR A, VCR B, VDP -' VIDEO
I OUTPUT............... 62 d8
Frequency response (video signal)

6. 5 HZ~ID MHz-3 dB
AU DIO INPUT sensItIvIty/Impedance
.................................. -6 LIBS/47 kohms
AUDIO OUTPUT level/Impedance
.................................. -6 st/47 kohms
SignaHo-noise ratio (IHF- A)
VCR B VDP -9 VCR A OUTPUT
...... Better than 80 d8
CR B, VDP 4 AUDIO
OUTPUT..,............ Better than 80 dB
Frequency response
VCR B, VDP -r VCR A OUTPUT
............................. 20 Hz~100 kHz -3dB
VCR A, VCR B, VDP - AUDIO
OUTPUT.. 20 Hz~100 kHz -3 d8
VHF OUT sign 3 ch or 4 ch

Audio section
CAUTION '"PXL5I§":I':{§IT¥2IZSEAY
- - - . o w k I
1. Parts Identified by theAsymboI on the schematic MIC. (I): :V/fg kghé':
dIagram and the parts IIst are wheel for safety. signal...»

Use only replacement parts that have critical charac- AuDIO INPUT. TAPE PLAY -r

teristics recommended by the manufacturer. AUDIO OUTPUT-r- Better than 80 dB
. MIC 4 AUDIO OUTPUT
2. Make leakage-current or reelstance measurements ............................. Better than 50 dB

to determine that exposed parts are acceptably in- Frequency mponse

sulated from the supply circuit before returning the 21%ISP83TIS'? PTLQYHZ~ 100 kHz 3 as
appl'ance to the CUSIomer- Output level/Impedance. 150 mVI2.2 kohms
Maximum output IeveI IV
Total harmonic distortion
AUDIO INPUT, TAPE PLAY -0

AUDIO OUTPUT... Less than 0.08% at 1 kHz
dbx noise reduction effect -30 dB at I kHz
NOISE FILTER ................. 3 kHz ~6 dB/oct

Others
Power requirements ........ 120/220/240V
50/60 Hz
For U. S A. and Canada
.IZOV (60 HZ)
33 watts (with camera)
.430 mm (16-15/16'IW
76 mm (3)H
265 mm (10-7/16")D
Weight ............................ 3.7 kg (8.2 lbs) net
4.6 kg (10.1 lbs) packed

Power consumptmn
Dimensions.

' Design and medication: subkcl to change without mike {or Im~
prom-Mun.

In older to simplify the uphnwon Mutilation; may sometimes We: (mm
the odynlls.

Sansuj.
SANSUI ELECTRIC CO., LTD.

Page 2

AV-77

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.

.. Manufactured for U.S.A market.
(UndenNriters Laboratories approved model.)
Manufactured for Canadian market.

. Manufactured for South African market.

. Manufactured for United Kingdom market.
Manufactured for European market.
Manufactured for Australian market.

XX (EXPORT). . Standard Version.

NON MARK ........ Common Parts.

. Some printed circuit boards are not supplied as the assembled.

To separate these in this service manual, the stock Nos are not in-
dicated at the ends of the board names. However, the individual parts
on the circuit boards are provided by orders.

. 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 E.B.L. : Low Leak BI-Polar

S.Fl. : Solid Resistor Electrolytic Capacitor

Ce.R. : Cement Resistor Ta.C. : Tantalum Capacitor

M.R. : Metal Film Resistor F.C. : Film Capacitor

F.R. : Fusing Resistor M.P. : Metalized Paper Capacitor

N.I.R. : Non-lntlammable Resistor Prc. : Polystyrene Capacitor

A.R. : Array Resistor G.C. : Glmrnic Capacitor

C.C. : Ceramic Capacitor A.C. : Array Capacitor

C.T. : Ceramic Capacitor. V.R. :Variabte Resistor
Temperature Compensation S.V.R. : Semi Variable Resistor

E.C. : Electrolytic Capacitor SW. : Switch

E.L. : Low Leak Electrolytic Chip R. : Chip Resistor
Capacitor Chip C. : Chip Capacitor

E.B. : Bi-Polar Electrolytic

Capacitor

Page 7

4. ADJUSTMENT

A. dbx Time Constant Adjustment

AV~77

Adjustment Procedure checked Position

Adjusted Parts

Adjustment Contents

Adjusting Conditions

Connect a DC
voltmeter
across time
constant test
pin (points a
and b) of
board F-4709.
(See Bottom
View on page
1 3.)

1 dbx time constant
adjustment

XVR1
(F4709)
(See
Bottom
View on
page 13.)

DC1510 mV

dbx switch ..... REC

B. Video Effector Adjustment
'Required Test Equipments

1, VHS Type Video Cassette Recorder (VCR) for NTSC or PAL system

2. Test Tape MH-l or MH-2

3. Monitor TV (or Home TV with RF Tuner)

Adjustment Procedure Checked Position

Adjusted Farts

Adjustment Contents

Adjusting Conditions

View on page
13.

1 Burst Flag Gate Connect an rVR14 1.Check that waveforms in VIDEO 1.Connect VCR to VCR A VIDEO IN
(BFG) adjustment oscilloscope (F-4706) FADER-IN should be as follows: terminal.
to video mo- See Cchromatic signal 2.VIDEO ART ..... OFF
nitor terminal. Bottom firmness 3.5HARPNESS, DETAIL . Full
(The output View on 59"al counterclockwise
terminal is at page 13. 4.Reproduce color bar signals of a test
75 ohms at tape by VCR.
its end.) 'NTSC System test tape
2.Check that waveforms in VIDEO
_ . MH-1 [Standard Play) Stock No,
FADER OUT should be as follows. 36805000
Segment Pllyblck Timl Vidln Sign-I Audio Signal
50 burs! signal Horizontal synchronizing 1° ""m 5"° 7 1
(nearly 353 MHz) sign-l (nalrlv 15 kHz) 2 5 MW, . mm, a m,
3.Turn rVR14 to adjust SC burst a .0"..an cm... H,
signal as shown. A a I m n; ( )
rnn s w
'Maladjustrnent ' "p "m
(Excessive turning of rVH14 clockwise) 0P AL System test tape
!\ ! MH-2 Stock No. 36809300
so burst signal
Slornent Pltvhlck 'l'Irnl Video Sifinol Audio Signal
(Excessive turning of rvnl4 counterclockwise) 0 mm 5mm 5 W
«Chromatic signal _
2 5 rnlnutn (none) 3 kHz
Cl '0 mlntmn color her I kHz 0 dB
SC bun Sign A 3 minutes RF may inane)
-Correct adjustment
U sc burst signal U
2 DC level Connect a DC rVRlO DC 1.6:0V Power switch ..... 0N
adjustment voltmeter be- (F-4706)
(Picture effect tween rD10 See
adjustment) anode (point Bottom
0) and +5V View on
(point d) of page 13.
F-4706.
See Bottom
View on page
13.
3 WHITE level Connect a DC rVR11 DC 750::10mV Power switch ..... 0N
adjustment voltmeter be- (F4706)
(ART-1 brightness tween (Will See
adjustment) (point e) and Bottom
+5V (point all View on
of F-4706. page 13.
See Bottom