Technics RS-CH770 User manual

ORDER NO. AD9603056C8
Service
Manual
Stereo
Cassette
Deck
Cassette
Deck
System:
SC-CH770
OU
[DOLBY
B
NR
|*’
R
S
=
C
+
vA
vA
O
*2.*3
§B-CH770
*2,*3
SB-PC10
*2.*9
SB-CH770
ST-CH770
SL-CH770
Colour
(K) : Black
ySBPSIO poe
Suffix for Area Colour
Model No.
Europe, Asia, Latin
America, Middle East,
Africa and Oceania
*2,*3 SB-PS10
RS-CH770 SE-CH770 Remote Control
Transmitter
System: SC-CH570
*2.*3 §B-CH570
*2.*3 SB-PC570 *2.*3 SB-CH570
*2
$B-PS570
#
*2$B-PS570
*1:
Dolby
noise
reduction
manufactured
under
or
i
i
i
or
license
from
Dolby
Laboratories
Licensing
*3SB-PS10
|
So
ee
as
|
gai?
SB-PS10
Corporation.
:
as,
re
“Dolby”
and
the
double-D
symbol
are
trade
marks
of
Doiby
Laboratories
Licensing
Corporation.
Remote Control
Transmitter
RS-CH770 SE-CH570
AR-2 MECHANISM SERIES
Specifications
(IH
F
78)
Frequency
response
(Dolby
NR
off)
.
TYPE
I
(NORMAL)
20
Hz-1
6
kHz
(DIN)
@
Cassette
Deck
Section
TYPE
II
(HIGH)
20
Hz-1
6
kHz
(DIN)
Deck
system
Stereo
cassette
deck
TYPE
IV
(METAL)
20
Hz-1
6
kHz
(DIN)
Track
system
4-track,
2-channel
S/N
(signal
level
=
max
recording
level,
TYPE
II
type
tape)
Recording
system
AC
bias
NR
off
56
dB
(A
weighted)
Bias
frequency
100
kHz
Dolby
NR
B
on
66
dB
(A
weighted)
Erasing
system
AC
erase
Input
sensitivity
and
impedance
Heads
REC
(IN)
400
mV/23
kQ
DECK
1
Playback
head
(Permalloy)
x
1
Output
voltage
and
impedance
DECK
2
Recording/Playback
head
(Permalloy)
x 1
PLAY
(OUT)
280
mV/360
O
Erasing
head
(Double-gap
ferrite)
x
1
Hi
General
Motors
: ;
DECK
1,
2
Capstan
drive
(DC
servo
motor)
=
1
Dimensions
(W
x
Hx
D)
270
x
118.5
«
269.5
mm
Tape
speed
4.8
cm/sec.
weelant
1.9
kg
Wow
and
flutter
0.16%
(WRMS)
Notes:
Fast
forward
and
rewind
times
Specifications
are
subject
to
change
without
notice.
Approx.
110
seconds
with
C-60
cassette
tape
Weight
and
dimensions
are
approximate.
Tuner/sound Compact disc el
System
processor
player
Amplifier
Cassette
deck
|
Front
speakers
|
Center
speaker
|
Surrournd
speakers
SC-CH770
ST-CH770
SL-CH770
SE-CH770
¥2.*3SB-CH770
|
*2°°SB-PC10
|
*°°3
SB-PS10
*2 SB-PT570
SC-CH570
ST-CH570
SL-CH570
sE-cH5s70
|
FS
CH770
|
s2s358.cH570
|
“SB-PCS70
*2SE3-PS570
*3SB-PT570A
*3 SB-PC570 “8S B-PS10
*2 For Europe area: oo... Made in PAES
*3 Except for Europe area: ..... Made in NABEL
© 1996 Matsushita Electric Indusiriaal Co., Ltd.
e ® :
All rights reserved. Unauthorized c ©pying i
ec
]
and
distribution
is
a
violation
of
law.
re

RS-CH770
A\WARNING
This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not
contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or
repair the product or products dealt with in this service information by anyone else could result in serious injury or death.
Location of- Controls iscetei es hick aie eee eisai etanariann Cotas aks 2 Wiring Connection Diagram
Operation Check and Function oflG Terminals: 23, ccecsse.cscesecesdauseavivesctds ay tice vals aan
Main Component Replacement Procedures 0... eee 3~12 Block Diagram .......ccceeccseetseetereee
Service Mode Function of Cassette Mechanism... 13,14 Replacement Parts List oe
Measurements and Adjustments ........ cece ecceceeeerserecteeetiieens 15~17 Cabinet Parts’ Location iin. ii. itie ities aude eens neinarieaGane
Schematic Diagram occ erect eeseeeereees Mechanism Parts Location
Printed Circuit Board Diagram uo... cece ce cererrseeeeeetsereeeens
NOTE:
Refer to the service manual for Model No. SE-CH770 (ORDER No. AD9603055C8) or SE-CH570 (ORDER No. AD9603054C8)
for information on “Accessories”, “Stacking the Components”, “Connections” and “Packaging”.
@ Location of Controls
G@) Deck 1 cassette holder
@ Deck 1 indicator (DECK 1)
3) Deck 1/deck 2 select button (DECK 1/2)
(4) Reverse mode select button (REV MODE)
() Deck 2 cassette holder
© Dolby noise reduction button (DOLBY NR)
@ Record pause button (@ REC PAUSE)
Record pause indicator (REC PAUSE)
@) Deck 2 indicator (DECK 2)
Deck 1 cassette holder open button (4 OPEN)
@) Counter reset button (RESET)
42) Counter display button (DISPLAY)
(3 Fast forward/rewind/tape program sensor buttons
(<<, >>)
Playback buttons and indicators (<1, >>)
@® Stop button (0)
Tape edit buttons (TAPE EDIT, NOR, HIGH)
@) Deck 2 cassette holder open button (4 OPEN)

RS-CH770
i OPERATION CHECKS AND MAIN COMPONENT REPLACEMENT PROCEDURES
1. This section describes procedures for checking the operation of the major printed circuit
boards and replacing the main components.
2. For reassembly after operation checks or replacement, reverse the respective procedures.
Special reassembly procedures are described only when required.
3. Select items from the following index when checks or replacement are required.
4. illustrated screws are equivalent to actual size.
5. Refer the parts No. on the page of “Main Component Replacement Procedures”,
if necessary.
e Contents
*Checking Procedure for each P.C.B. Page.
1. Checking for the main P.C.B. and power supply P.C.B..sseeeceeecceecccsccccccccccescsecescvses ee 34.
2. Checking for the operation P.C.B.. Coo omer eererererereseesereoesreesereenecseneseseeeeeoer oe 56,
«Main Component Replacement Procedures
1. Replacement for the cassette lid ass'y, se eereecereccccsccsescesescccssesceseseeseesesvvcsvoce 7.
2. Replacement for the cassette holder, s*eeecercsccsccrvecvereeccccveesesesesesesesesesecesenes 7:
3. Replacement for the motor ass’y, capstan belt and winding belt. sesercerreseeccceercesccscscveeeeeee 8.44,
4. Replacement for the plunger ass’y and the parts mounted on mechanism P.C.B.. seeececerceeesesccevess 14.42,
5. Replacement for the head block and pinch roller ass’y.sseesecceccesccsvccsscsscessscescsecsceve se t2
Mi Checking Procedure for each P.C.B.
1. Checking for the main P.C.B. and power supply P.C.B.
Remove the top cabinet.
Cup
@x4
()\ mp © (Black)
[RHD30007 - K1]
(ID © Black)
[XTBS3+8JF-Z1]

RS-CH770
Remove the flat cable
from connector. cD
Release the 4 claws, and then
remove the front panel ass’y.
Connector
(CN901-—1/CNS01—2)
Main P.C.B.
Connect the
flat cable to
the connector.
Connector
(CN6O1A)
Release the 2 claws,
and then remove the
power supply P.C.B..
Socket
(CN601B)
Power supply P.C.B. t step 9
Connect the socket (CN601B)
to the connector (CN601A).
* Check the main P.C.B. and power supply P.C.B.
as shown below.
Main P.C.B.
istep 10)
Connect the
lead wire.
Cabinet
Place the power supply P.C.B.
on the insulation material not
to short-circuit the solder side
of power supply P.C.B..
(i) + (Black)
[XTBS3HJFZ1]

RS-CH770
2. Checking for the operation P.C.B.
Press the eject rod in
the direction of arrow,
and then open the
cassette holder.
+ Follow the @eamp ~ of the item 1 in checking
procedure for each P.C.B. on pages 3 and 4.
Cassette holder
(DECK1)
Cassette holder
(DECK2)
Remove the shield plate
(L) / (R).
Shield plate (L)
Shield plate (R)
Release the claw, and then
remove the mechanism unit.
Remove the cassette lid ass’y
in the direction of arrow.
Cassette lid ass'y
(DECK1)
Cassette lid ass’y
(DECK2)
Release the 2 claws.
(SID © (Black)
[XTB3+1 OJFZ]
(3) ‘bY
[XTBS26+10J]

RS-CH770 |
Remove the deck mecha frame
in the direction of arrow.
Remove the operation P.C.B..
Operation P.C.B.
Connect the flat cable
to the connector.
\
Connector (CN601A)
Socket (CN601B)
Power supply P.C.B. aD
Connect the socket (CN 601B)
to the connector (CN6(4A).
¢ Check the operation P.C.B. as shown below.
Operation P.C.B.
Connect the lead wire
NOTE
Place the power supply P.C.B.
on the insulation material! not aes
to short-circuit the solder side
GND plate
of power supply P.C.B..
Cabinet
eae

| _ RS-CH770
i Main Component Replacement procedures
1. Replacement for the cassette lid ass’y
+ Follow the G2aD ~ GED of the item 1 in checking
procedure for each P.C.B. on page 3.
Cassette holder (DECK2)
Cassette holder (DECK1)
c=
Press the eject rod in the
direction of arrow, and then
open the cassette holder.
Eject rod
Remove the cassette lid ass’y
in the direction of arrow.
Cassette lid ass'y (DECK1)
(RYF0412-K]
Cassette lid ass'y (DECK2)
[RYF0413-K]
2. Replacement for the cassette holder
* Follow the G&D ~ GEEED of the item 1 in checking
procedure for each P.C.B. on pages 3 and 4. M@ Open spring installation
*
Follow
the
ZUR
~
of
the
item
2
in
checking
Cassette
holder
ass'y
procedure for each P.C.B. on pages 5 and 6. (DECK1)
[RFKLACH430GA]
Cassette holder
ass y (DECK2) ——,
[RFKLACH430GB]
» Release the lug
of
Cassette
holder
Sy
in
the
direction
of
arrow.

RS-CH770
3. Replacement for the motor ass’y, capstan belt and
winding belt
+ Follow the @25ED ~ GREED of the item 1 in checking
procedure for each P.C.B. on pages 3 and 4.
* Follow the G&D ~ G&D of the item 2 in checking
procedure for each P.C.B. on page 5.
Mechanism
P.C.B.
SG
5
|
aun
qs,
NOTE
Kr
ie
Ea
wi
ue
Handle
the
connector
)
aN
:
;
with
care
so
that
me
When
removeing
the
Oe
4
3
LTS:
a
shape
of
terminals
mechanism
control
P.C.B.,
;
be
toe
Rae
nae
i.
:
different
from
others.
remove
it
with
holding
the
¥
=
mechanism
P.C.B.
by
finger.
Unsolder the
terminals.
Release the claw, and then
remove the main P.C.B..
The illustration below shows DECK2 mechanism.
For DECK1 mechanism, perform the same
procedure
as
DECK2.
Remove
the
sub
chassis.
Head connector
Re
€ its
Remove the
P.C.B. support.
ex)
hs
;
(se)
ump
ra)
Release
the
2
claws,
:
and
then
remove
the
.
head connector. a : XTBS26+8]
f)ump ©
XTW26+10S]

RS-CH770
@)p ©
[RHD26022]
Motor ass'y
[REM0055]
Capstan belt
[RDV0034]
Remove the flywheel R.
Winding belt
[RDV0033-1] | Release the 2 calws, and then
step
11
remove
the
winding
belt
and
Remove
the
flywheel
F,
SPN9-
Put the winding belt on the flywhe el F.
Veh
The boss and marking
should be positioned
horizontally.
F lywheel F
Winding belt
Tweezers
Install the flywheel F.
NOTE
Take care not stick the grease onthe belt.
Put the winding belt on
the pulley temporarily.

RS-CH770
The winding lever should be
positioned as shown below.
Winding lever
Capstan belt A
(Side view)
Winding arm
Install the winding lever and spring while pressing
the winding arm in the direction of arrow.
(The winding lever must be inserted completly and
latched with claws.)
Put the capstan belt A temporarily
as shown below.
dss 505:
Boss
Capstan belt A
Install the sub chassis
to the mechanism, and
then tighten screws.
Mechanism
~10-
@)mm 0
[XTW226+10S]