Kenwood KA-7090R User manual

STEREO INTEGRATED AMPLIFIER
KA-7090R
KENWOOD
SERVICE MANUAL
© 1996-7/B51-5209-00 (K/K) 1949
Knob
(K29-3759-14)
Knob
(K29-6391-04)
Knob
(K29-6390-04)
KENWOOD
INPUT SELECTOR VOLUME CONTROL
en
REMOTE POWER
| :
‘ORS aNTBY
MAIN POWER
——
ON OFF SPEAKERS A B SOURCE DiRECT LOUDNESS REC OUT
SPEAKERS
oF ke ®
RHONES:
rey
SOURCE
GREC]
—
LOUCNESS
REC
OUT
ATT
-3008
=MM
MC
a ®
STEREO INTEGRATED AMPLIFIER
KA-7090R|
Knob Dressing plate Knob
(K27-2176-04)
(BO3-2972-13)
(K29-3759-14)
Phono jack Miniature phone jack Slide switch
(E63-0099-05) (E11-0293-05) (S62-0034-05)
Screw terminal board
(E70-0063-05)
Power cord bushing
(J42-0083-05)
} LIE X58:
SL16 xse
SIGNAL GND '
@QO©O@O©@E@©
oe Ss 12h oes pee
UNSW TCHED.
Phono jack Phono jack
(E63-0098-05) (E63-0099-05) AC outlet * AC power cord *
Phono
jack
(E03-)
(E30-)
(E63-0102-05)
* Refer to parts list on page 26.

KA-7090R
CONTENTS / ACCESSORIES
Contents
CONTENTS / ACCESSORIES ......e.ecccecceeeeeeeeees 2 SCHEMATIC DIAGRAM
DISASSEMBLY FOR REPAIR..........cccccsseseseseseseseseeees 3. EXPLODED VIEW cesseccceccccscesssccessessotessecstvncccnnnatscvevs
CIRCUIT DESCRIPTION Sic iinet anni: Ar. JPARTSIISE cucu ateninmauinidenimwnaecueonataed
ADJUSTMENT stcigesieicheadyuetaletdeesl eatecs puestd wteaka 11 SPECIFICATIONS se3x iss Gatien anennineawoate
PC BOARD s cictrctecinitertutesnsccnicuastitiassincsithootevvaitantis 13
Accessories
Remote control unit
(A70-1079-05)
Battery cover (A09-01 70-08)

|
KA-7090R
) DISASSEMBLY FOR REPAIR
HOW TO REPLACE POWER TRANSISTOR
1. Remove 5 screws (@)fixing audio pcb (X09).
2. Remove left side screws (@).
3. Remove panel top screws (@), panel bottom screws(@) and fram screw(@).
4. Remove bottom screws(Q), rear screws(@) and bottom plate.
5. Lift unit to arrow direction(®). (Power transformer is bottom side)
6. Replace power transistors.

KA-7090R
CIRCUIT DESCRIPTION
1. FUNCTION
(1) FEATURE
_ AUDIO INPUT _
“REC OUT
* K’s is Japanese market only.
COMPO(KA-7090R)
TAPE, MD, CD, AUX, TUNER, PHONO |
TAPE-MD, MD-TAPE
_ CD, AUX, TUNER, PHONO
DIRECT
LOUDNESS __
MD/MONITOR
~ REMOCON
SYSTEM CONTROL
SOURCE DIRECT
MOTOR VOLUME
f
if
© (8/16) |
HEADPHONE
SPEAKER |
BACK UP
2. MODEL CONDITION
eee
A /B/A+B/ OFF
an
s_)
“SOURCE DIRECT
__CD DIRECT.
A /B/AsB/ OFF
PORT2 (SERIAL / MODEL)
H
COMPO (KA-7090R) _
SERIAL 8 bit
K's
KAF-7002
L
SERIAL 16 bit
KAF-5002
3. INITIALIZING FUNCTION
3-1. Initializing Operation
- Insert the AC power (set the POWER key to ON) for initialization while pressing the ON/STAND_BY key even if the system
is in the backup state.
- After the microcomputer is reset, set the port, modes, and register, then check each key.
* If the ON/STAND_BY key is pressed, perform the RAM ALL CLEAR operation for initialization.
* If the ON/STAND_BY key is not pressed, check whether the system is in the backup state.
* Pull out the AC power (set the POWER key to OFF) to destroy the backup data while pressing the ON/STAND_BY key.
3-2. INITIAL STAGE
FUNCTION
| COMPO (KA-7090R) _
ON/STAND-BY
MODEL
KAF-7002
SYSTEM OFF
SYSTEM OFF
__ INPUT SELECTOR
REC OUT
TUNER
TUNER
_KAF-5002_
SYSTEM OFF
i INE
REC
MODE
OFF
(OFF)
LOUDNESS
DIRECT
SOURCE. DIR
MD/MONITOR
OFF
eile th
DIRECT OFF
OFF
DIRECTOFF
MUTING
. BACK UP DATA
WHEN STAND-BY
DESIGNATION
_ INPUT SELECTOR
| COMPO (KA-7090R) _
SELECTOR CONDITION
OFF _
OFF.
OFF
MODEL
OFF
KAF-7002
SELECTOR CONDITION |
KAF-5002
SELECTOR CONDITION
‘REC OUT POS
LOUDNESS)
DIRECT
SOURCE. DIR
___ MD/MONITOR
MUTING
ON/OFF CONDITION
ON/OFF CONDITION —
DIRECT CONDITION |.
_ ON/OFF CONDITION
DIRECT CONDITION
S. DIR CONDITION _
~ MUTE CONDITION
_ ON/OFF CONDITION
MUTE CONDITION
ON/OFF CONDITION
MUTE CONDITION

KA-7090R
CIRCUIT DESCRIPTION
5. TEST MODE
5-1. Test Mode using Main Unit’ s Keys
(1) Setting the test mode
Turn on the power while pressing the “LOUDNESS”
key.
(2) Canceling the test mode
- To initialize the system and cancel the test mode, turn off
the power.
(3) Contents of test mode
+ The muting during mode selection is not controlled in the
test mode. However, the operation when the power is
turned on is the same as for the normal operation.
+ The speaker protection operation is also the same as for
the normal operation.
(4) Automatic POWER ON
+ The POWER ON state is entered for model discrimina-
tion whenever the power is turned on while pressing the
“LOUDNESS” key. All the functions are then initialized
and activated in the all-lighting mode.
In the all-lighting mode, the selector display LED lights
sequentially. For KAF-7002/5002, the SOURCE DIRECT
and CD DIRECT display LEDs light alternately. For KA-
7090R, the SOURCE DIRECT display LED lights. The
SP A and B display LEDs do not light. All other LEDs
light.
- The all-lignhting mode is canceled when any of the main
unit’ s keys is pressed. The normal display obtained
when the selector is set to TUNER then appears.
(5) Special operation
“LOUDNESS” key
(a) When this key is pressed, the LOUDNESS display
LED lights and the electric volume turns up for 16 sec-
onds. After 16 seconds, the electric volume stops and
the display LED goes off.
(b) When this key is pressed during operation or after
operation in step (a), the LOUDNESS display LED lights
and the electric volume turns down for 16 seconds. After
16 seconds, the electric volume stops and the display
LED goes off.
(c) When this key is pressed during operation in step (b),
the LOUDNESS display LED goes off and the electric
volume stops.
(d) The operation in step (a) is carried out when this key
is pressed after operation in step (c). After that, the oper-
ation in steps (a) to (c) is repeated every time this key is
pressed. The operation is not canceled even if another
key is pressed while the electric volume turns up and
down.
» “SPEAKER A+B”
When the switch is set to this position, the SPEAKER A +
B LED (for only the KA-7090R) lights and the audio mut-
ing is turned on. When the switch is set to another posi-
tion, the LED goes off and the audio muting is turned off.
“MD MONITOR” key (for only KAF-7002/5002)
When this key is pressed, the MUTE display LED lights
and the audio muting is turned on. When this key is
pressed again, the audio muting is turned off and the dis-
play LED goes off.
- “ATT. -30dB” key (for only KA-7090R)
When this key is pressed, the ATT. LED lights and the
ATT. -30dB is turned on during normal operation. The
REC muting is turned on while the REC OUT mode is set
to ON. When this key is pressed again, the ATT. or REC
muting is canceled and the ATT. LED goes off.
“REC OUT” key (for only KA-7090R)
When this key is pressed, the REC OUT LED lights and
the REC OUT mode is set to ON. The operation is not
canceled until this key is pressed again. The REC mut-
ing is canceled if it is on when the operation is canceled.
“8/16-bit selector switch” (for only KA-7090R)
The system enters the all-lighting mode if this switch is
set to the 8-bit position when the ATT. key is on after the
all-lighting mode is canceled. The serial POWER ON
code is output at that time (code “25H” is output when
the test mode is activated in the 8-bit position, and code
“0800” is output when it is activated in the 16-bit posi-
tion). The all-lighting mode is canceled when this switch
is set to the 16-bit position again or when the ATT. key is
pressed. The normal display then appears.
5-2. Serial Test Mode
(1) Setting the test mode
.
The serial test mode is entered if a serial “71H” code
is received only when the KA-7090R is in the 8-bit mode.
After that, only the 16-bit mode is accepted. In other
cases, the serial test mode is entered when a serial
“C27FH” code is received.
(2) Canceling the test mode
The serial test mode is canceled when a “C27FH”
code is received. In this case, the system is not initial-
ized. The serial code also remains set to the 16-bit posi-
tion.
- When the AC power (main power) is turned off, the serial
test mode is canceled and the system is initialized.
(3) Contents of test mode
.
.
The serial code for a test shown in the attached list is
analyzed for processing.
In the test mode, no mute signal is output to shorten the
input/output selection time during measurement. Howev-
er, the operation when the power is turned on is the
same as for the normal operation.
The speaker protection operation is also the same as for
the normal operation.- The code input in the test mode by
serial communication is validated irrespective of the dis-
play mode.

KA-7090R
CIRCUIT DESCRIPTION
- The all-lighting mode is canceled using an all-lighting
cancel code. After cancellation, the normal display
appears.
- In the all-lighting mode, the selector display LED lights
sequentially. For KAF-7002/5002, the SOURCE DIRECT
and CD DIRECT display LEDs light alternately. For KA-
7090R, the SOURCE DIRECT LED lights. The SPEAK-
ER LED does not light. All other LEDs light.
- The REC OUT selector is operated by inputting the code
of the selector after a REC MODE ON code is input (for
only KA-7090R).
+ The main unit’ s keys can be pressed even in the serial
test mode. However, the operation is not guaranteed in
this case.
+ The operation when the code having a function not con-
tained in the corresponding model is input is not guaran-
teed.
+ The REC muting is canceled by MUTE ALL OFF.

KA-7090R
CIRCUIT DESCRIPTION
6. Microprocessor periphery block diagram
(K's KAF-7002,5002)
(KA-7090R)
POWER ON x 1
AUDIO MUTE x 1
HEAD PHONE x 1
— SERIAL x2
DATA, BUSY
r- MOTORVOL x2
UP/DOWN
L
AD x3
KEY INPUT
SP SW INPUT (ROTARY SW)
INPUT INPUT (ROTARY SW)
SELECTORIC x3 (K's)
DATA, CLOCK, BUSY
TC9162 (FUNCTION SW)
TC9164 (REC OUT SW)
SELECTOR IC x 5 (KA-7090R)
- DATA, CLOCK
- BUSY (TC916X)
- CLR, STB(NJU3711)
TC9162 (FUNCTION SW)
TC9164 (REC OUT SW)
NJU3711(INPUT SEL SW)
LED DISPLAY x13
SELECTOR LED
/RELAY CONTROL x6
REC OUT LED x 1
A.T.T. LED x1
ON/STANDBY LED x 1
LOUDNESS LED x 1
S. DIRECT LED x 1
SP RELAY x 2
(KA-7090R)
LED DISPLAY x 14
SELECTOR LED x 6
MD/MONITOR LED x 1
MUTE LED x 1
ON/STANDBY LED x 1
LOUDNESS LED x 1
DIRECT LED x 2
SP RELAY x 2
(K's)
(K's KAF-7002,5002)
DIRECT ENCODER x2
REMOCON x1
PROTECTION x1
RESET x1
CE x1
=
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sl
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feat
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D
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DESTINATION x2
COMPO/K's DISCRIMINATION
8/16 bit CHANGE OVER(KA-7090R)
DESTINATION x2
COMPOKK's DISCRIMINATION
KAF-7002/5002 DISCRIMINATION
(K's)

KA-7090R
CIRCUIT DESCRIPTION
6-1. Microprocessor pin connection
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go
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SDNVHOS1/8
——
' NOILVNILSAG
| NOILVNILSSO
wOCOLYS
Sid
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KA-7090R
) CIRCUIT DESCRIPTION
) 16bit serial test code (C2XXH)
TYPE
FUNC
0
1
2
E
F
:Sendingcode
|}:

6-2. Pin connection
NAME
KA-7090R
CIRCUIT DESCRIPTION
DESCRIPTION
DESTINATION 14
COMPOKK's DISCRIMINATION PORT
POWER ON
POWER RELAY CONTROL TERMINAL
COMPO CLR
xIyjrc\|r
CONTROL IC(NJU3711)CLR SIGNAL OUTPUT TERMINAL(KA-7090R)
NOT USED
Ti rly
K's MD MONITOR
“REC OUT" LED CONTROL TERMINAL (KA7090R)
"MD MONITOR" LED CONTROL TERMINAL
MUTING-30
COMPO “AeTeT" LED RELAY CONTROL TERMINAL (KA-7090R)
K's "A MUTE” LED TERMINAL
AUDIO MUTE
"MUTING" SIGNAL OUTPUT TERMINAL
HEAD PHONES
ps ee Oe
HEAD PHONES CONTROL TERMINAL
CTlrcjir
S DATA
SERIAL DATA
S BUSY
SERIAL BUSY
V DOWN
VOLUME DOWN SIGNAL OUTPUT TERMINAL
Vv UP
VOLUME UP SIGNAL OUTPUT TERMINAL
KEY (TACT)
| KEY INPUT TERMINAL
5 KEYS (KA-7090R)
KEY INPUT TERMINAL 5 KEYS (K's)
SPEAKER SEL
" SPEAKER SELECTOR “ INPUT TERMINAL
SEL IC DATA
SELECTOR IC DATA
SEL IC CLOCK
SELECTOR IC CLOCK
SEL IC ST
SELECTOR IC STROBE
INPUT SEL
V REF
INPUT SELECTOR SW INPUT/CONTROL TERMINAL
A/D REFERENCE VOLTAGE
X IN
OSCILLATOR (8MHz)
X OUT
OSCILLATOR (8MHz)
VSS
GND
VCC
+5V
NOT USED
MICROPROCESSOR CHIP ENABLE : ENABLE
RESET
RESET SIGNAL INPUT TERMINAL
PROTECTION
PROTECTION DETECTION
REMOCON IN
REMOTE CONTROL INPUT TERMINAL
SOURCE.DIR B
; COMPO — NOT USED
K's ROTARY ENCODER B SIGNAL INPUT TERMINAL
SOURCE.DIR A
COMPO — NOT USED
K's ROTARY ENCODER A SIGNAL INPUT TERMINAL
SP B
SPEAKER RELAY B CONTROL TERMINAL
SPEAKER RELAY A CONTROL TERMINAL
lou Renke)
COMPO(NJU3711)CONTROL ST SIGNAL OUTPUT TERMINAL (KA-7090R)
K's "CD.DIR"LED CONTROL TERMINAL
Tr | T| er
SOURCE DIR
"“SOURCE.DIR"LED CONTROL TERMINAL
LOUDNESS
"LOUDNESS" LED CONTROL TERMINAL
ON/STANDBY
“ON/STANDBY" LED CONTROL TERMINAL
INPUT TAPE
"TAPE" LED/RELAY CONTROL TERMINAL
MD
"MD" LED/RELAY CONTROL TERMINAL
cD
"CD" LED/RELAY CONTROL TERMINAL
AUX
"AUX" LED/RELAY CONTROL TERMINAL
TUNER
"TUNER" LED/RELAY CONTROL TERMINAL
PHONO
0;0/0/0)/0}/0;0; 0/0
"PHONO" LED/RELAY CONTROL TERMINAL
COMPO 8/16
K's DESTINATION2
SERIAL 8/16 BIT DISCRIMINATION TERMINAL (KA-7090R)
: KAF-7002
MODEL DISCRIMINATION TERMINAL
: KAF-5002 rc