Kenwood RSG-7 Service manual

STEREO INTEGRATED AMPLIFIER/TUNER

70%

604 603 614 611 642

640612641 613

∞ ∞

stereo integrated amplifier/tuner

phones

down up

volume
control

pure

input selector

N.B./tone

pure

enter

%

band

auto/mono

fi turning

on/standby

SPEAKER
(6 – 16 Ω)

R

L

SUB
WOOFER
PRE OUT

FM75Ω

FM300Ω GND

AM

ANTENA

SYSTEM

CONTROL

R

L

IN IN

CD AUX

REC OUT

PLAY OUT

REC OUT

PLAY OUT

TAPE

MD

R-SG7/SG7G

SERVICE MANUAL

© 1999-7/B51-5549-00 (K/K) 2299

SUB panel *
(A22-)

AC cord *
(E30-)

Panel *
(A60-)

Knob
(K29-6741-04)

Front glass
(B10-2373-03)

AC cord bushing
(J42-0083-05)

Indicator
(B12-0368-04)

Knob
(K29-6358-14)

Metallic cabinet
(A01-3470-11)

Escutcheon
(B07-2457-03)

Indicator
(B12-0320-04)

Lock terminal board
(E20-0476-05)

Knob
(K29-7570-03)

Rectangular receptacle
(E08-0312-05)

Lock terminal board
(E70-0034-05)

Phono jack
(E63-1014-05)

Phono jack
(E63-0136-15)

* Refer to parts list on page 23.

Phono jack
(E63-0047-15)

R-SG7/SG7G

DISPLAY

SLEEPTAPE

REMOTE CONTROL UNIT

RC-SE9

1 2 3 RANDOM

4 5 6 CLEAR

7 8 9 P.MODE

O.T.E. 0 +10 EDIT

TUNER

BAND

INPUT N.B. MUTE

VOLUME

CONTROL

MD

CDP.CALL

Operation to reset

The microcomputer may fall into malfunction (impos­sibility to operate, erroneous display, etc.) when the
power cord is unplugged while power is ON or due to
an external factor. In this case, execute the following
procedure to reset the microcomputer and return it
to normal condition.

R-SG7
Pull the power plug from the receptacle, and then plug
it in again while keeping the “on/standby” key pressed.

÷Please note that resetting the microcomputer clears the

contents stored in it returns it to condition when it left the
factory.

CONTENTS / ACCESSORIES

Contents

CONTENTS / ACCESSORIES .................................. 2

CIRCUIT DESCRIPTION............................................3

ADJUSTMENT............................................................7

PC BOARD ................................................................ 8

Accessories

SCHEMATIC DIAGRAM.......................................... 11

EXPLODED VIEW ....................................................22

PARTS LIST..............................................................23

SPECIFICATIONS ......................................Back cover

AM loop antenna (1)
(T90-0833-05)

Audio cords (2)
(E30-0615-05)

Remote control unit (1)

(A70-1154-05) : M . . . . . . . RC-SE9

(A70-1155-05) : TE . . . . . . . RC-SE9(E)

AM loop antenna stand (1)
(J19-3645-05)

System control cord (1)
(E30-2628-05)

FM indoor antenna (1)
(T90-0801-15) : M
(T90-0809-05) : ET

Batteries (R6/AA) (2)

AC plug adaptor (1)
(E03-0115-05)

Battery cover (A09-0356-08)

2

R-SG7/SG7G

Desti-

nation

Band

Receiving

frequency

range

Channel

space

IF

PLL

reference

frequency

DIODE SW

DSW1 DSW2
(D519) (D518)

FM 87.5MHz~ 50kHz +10.7MHz 25kHz

E1 108.0MHz 0 1

AM 531kHz~ 9kHz +450kHz 9kHz

1602kHz

FM 87.5MHz~ 50kHz +10.7MHz 25kHz

E3 108.0MHz 1 0

(RDS) AM 531kHz~ 9kHz +450kHz 9kHz

1602kHz

M E1 changes by only setting " DSW1". (DSW1 0,E1) X 1

*DIODE SW(DSW) : 0 Without diode(when static, input low)

1 With diode(when static, input high)
X Switching transistor

CIRCUIT DESCRIPTION

1. INITIAL STATE

(1) AMP related block

• POWER ..............................OFF

• SELECTOR SOURCE ........TUNER

• DISPLAY..............................SELECTOR

• N.B.CIRCUIT.......................OFF

• A CLASS VOLUME VALUE

.............................................1.80 STEP

• AB CLASS VOLUME VALUE

.............................................9 STEP

• PURE A MODE....................NORMAL(AB CLASS)

• AUTO POWER SAVE..........OFF

(2) TUNER related block

• BAND...................................FM

• P.CH MEMORY...................LAST FREQUENCY

• LAST P.CH..........................01ch

• RDS DATA TABLE MEMORY

.............................................NO DATA

• RECEIVING FREQUENCY

.............................................LOWER LIMIT

VALUE OF
RECEIVING FREQUNCY
FM : 87.5MHz
AM : 531kHz

• AUTO/MANUAL...................AUTO

• EON THRUST RECEIVING MODE

.............................................OFF

(3) TIMER related block

• CLOCK ................................STOP(AM12:00)

• PROGR................................WORKIG MODE (OFF)

CONTENTS OF PROGRAM

.........................................ON=AM12:00

OFF=AM12:00
PLAY MODE=PLAY
SELECTOR=TUNER(1ch)
REC MODE=TAPE

• O.T.T....................................WORKING MODE (OFF)

O.T.T.ON TIME...............AM7:00

2. INITIALIZING

2-1 The method of the initializing

The system is initialized when the power is turned on while
pressing the [ON/STANDBY] key.
(1) Contents of the operation

• All the functions are initialized.

The microcomputer is reset when the AC power is turned
ON. The data for backup state comfirmation is checked
by reset processing. The microcomputer is initialized
when the data was destroyed. If it is not destroyed, the
microcomputer is started in the backup state.

• The data for backup state comfirmation is written in a
RAM area.

• The microcomputer is set to the stop mode so as to save
the power consumption.

• A backup state set command signal is detected by a timer
interrupt of 1 msec.

• The backup guarantee period is set in a circuit.

(2) Contents of backup data to be held

••• ••• ••• AMP ••• ••• •••

• POWER ON/OFF

• DISPLAY MODE

• SELECTOR SOURCE

• N.B.CIRCUIT MODE

• A CLASS VOLUME VALUE

• AB CLASS VOLUME VALUE

• PURE A MODE

• AUTO POWER SAVE ON/OFF

••• ••• ••• TUNER ••• ••• •••

• LAST BAND

• PRESET CHANNEL/RECEIVING FREQUNCY/PI/TA/
PTY/PS

• LAST RECEIVING FREQUNCY AND PRESETCHANNEL
(AM/FM)

• PRESET MEMORY DATA(1ch~40ch)

• AUTO/MANUAL

• EON THRUST RECEIVING FREQUNCY

••• ••• ••• CLOCK/TIMER ••• ••• •••

• LAST CLOCK DATA

• PROGRAMMED CONTENTS/PROGRAM TIMER
WORKING MODE ON/OFF

• O.T.T. SETTING TIME/WORKING MODE ON/OFF

4. CONDITIONS ACCORDING TO THE DESTINATION

4-1 Destination list of tuner

3. BACK UP

This function holds the current state of the unit even if the
AC power of the receiver is turned OFF.

(1) Operation outline

The backup state set command(CE) of a microcomputer
is set low when the AC power is turned OFF. The micro­computer detects the signal and enters the stop state.

3

R-SG7/SG7G

CIRCUIT DESCRIPTION

5. TEST MODE

5-1 AMP test mode using main unit's keys

• Entering the AMP test mode
Turn on the power while pressing the[BAND] key.

• Canceling the AMP test mode
By turning off the power, the systen is initialized and the
test mode is canceled.

5-1-1 Contents of AMP test mode

(1) Automatic on/standby ON

• The POWER ON state is entered when the power is
turned on whille pressing the [BAND]key. All functions are
then initialized and activated in the all-lighting mode.

• Sub-clock oscillation diagnosis function
The oscillation diagnosis (existence of oscillation and
measurement of period) of a sub-clock is performed
before the test mode is entered. If the diagnosis result is
OK,the system enters the test mode. If the diagnosis
result is NG,the oscillation of the sub-clock is diagnosed
again. If the result is OK, the system enters the test
mode. If the diagnosis result is continuously NG five
times, the system stops with ERR1 and ERR2 displayed.

(2) All- lighting mode

• All the fluorescent display indicators and LED lamps light
when the power is turned on while pressing the [BAND]
key. After that, all- lighting mode is canceled when any
main unit's key is pressed. The normal display is obtained
when the selector is set to TUNER then appears.

(3) Others

• The AMP test mode is not terminated even if the selector
is set to positions other than TUNER.

• In the AMP tesst mode,the muting during mode selection
is not controlled. However, the operation during the
power-on sequence is the same as the normal operation.

• The SP protection operation is also the same as the nor­mal operation.

• In the AMP test mode using main unit's keys,the keys
below provide a special operation according to the posi­tion where the selector is set. The main unit key's except
described below and the rotary encoder provide the nor­mal operation.

(4) When selector is set toTUNER

Keys Operation

PURE A Increase the P.CALL every time this key

is pressed.

N.B./TONE Decrease the P.CALL every time this key

is pressed.

ENTER Selects the display cyclically in the order

below every time this key is pressed.

3 Set the TUNER ATT to ON and the display S level in

hexadecimal when the [ENTER] key is pressed. (ATT ON
✽ ✽ is displayed in the fluorescent display indicator.)

* The special display using the [ENTER] key is continued

until the next operation is carried out. ( ✽ ✽ : S LEVEL)
When keys other then ENTER are pressed in items 1 to
3 above, the TUNER ATT is set to OFF and the normal
display appears. The operation corresponding to the key

that has been pressed performed in this case.
(5) When selector is set to positions other than TUNER.
1 ENTER and PURE A keys.

The master volume level is selected cyclically, while press-

ing the [ENTER] key.

Value of Master Press the Press the PURE A key,

volume. ENTER key. then press the ENTER key.

MAX 86 16.00

MID 40 8.00
MIN 1 0.20

2 AUTO/MONO key.

Selects the mute operation and equalizer cyclically in the

order below for operation display every time this key is

pressed.

KEY OPERATION

AUTO/MONO

*In the operation for except the AUTO key, become pre-

condition equalizer.

*Pre -condition : The equalizer becomes the condition to be

pushed the AUTO key before (include N.B. circuit).

3 BAND and tuning UP/DOWN keys.

KEYS OPERATION
BAND Every time this key is pressed, all

the displays go off and the normal
display is selected cyclically.

TUNING

UP/DOWN

1 Write data in the unused area of E2PROM, then read the

written data. If the read data is the same as the written
data, RAM OK is displayed in the fluorescent display indi­cator. If the former is the different from the later, RAM NG
is displayed.

2 Set the TUNER ATT to OFF and display the S level in

hexadecimal when the [ENTER] key is pressed . (ATT
OFF ✽ ✽ is displayed in the fluorescent display indicator.)

4

R-SG7/SG7G

X09,ED1

FL DISPLAY(FIP9GM6R)

RESET
CE
REMOCON

KEY MATRIX

LEVEL IN
CLASS A LED

FL GRID

43

916
BIAS MID IC11 3 X05,IC2
BIAS HI

PLL IC

LOW RELAY

(LC72131)

HI RELAY 1
SPEAKER RELAY

uPD78045FGF071 X09,IC1

(u-COM) 3

SELECTOR ANALOG

X09,J4

SW CONTROL IC

SERIAL DATA

(NJU7313AM)

BUSY

X09,IC3

X09,S516 2

E.VOL.IC

VOLUME

(M62421SP)

ROTARY ENCODER

2

ENC-A

SD

ENC-B

STEREO
HEADPHONES
PROTECTION

A MUTE
T MUTE
H.P. MUTE
ATT
A CLASS ON

KR0 KR1 KR2
KS0 DSW1(D519) DSW2(D518)
KS1 POWER AUTO/MONO BAND
KS2 N.B. CIRCUIT INPUT SEL. TUNING UP
KS3 pure A ENTER TUNING DOWN

5960
64
63
62

61

58

CIRCUIT DESCRIPTION

6. Microprocessor : uPD78045FGF071(X09-IC11)

6-1 Microprocessor periphery block diagram

Key matrix

signifies pin number of microprocessor.

b

5

R-SG7/SG7G

CIRCUIT DESCRIPTION

6-2 Pin description

Pin No. Pin Name I/O Description Active

1~7 7G~1G O FL grid7~1.

8 VDD - Microprocessor power supply (+5V).
9 E2PROM SCL I E2PROM control clock.

10 E2PROM SDA I/O E2PROM control data.

11,12 NC - Unused.

13 A CLASS ON O POWER ON/OFF control signal. H : ON L : OFF
14 SEL STB O Strobe signal of selector IC.
15 SEL/PLL/CLK O Control clock of SEL/PLL IC.
16 SEL/PLL/DATA O Control data of SEL/PLL IC.
17 RESET I Reset signal of microprocessor. L : Reset
18 CE I Detection signal input for AC OFF.
19 PLL DO I PLL IF count data.
20 AVss - A/D power supply(GND).
21 PLL CE O Chip enable control of PLL IC. L : ON
22 T MUTE O Output terminal of muting signal for TUNER. L : ON
23 STEREO I Stereo signal input for TUNER. L : Stereo ON
24 SD I Synchronized signal detection input.
25 VOL SCL O Control clock of E. volume IC.
26 VOL DATA O Control data of E. volume IC. L : CE
27 LEVEL IN I Volume level input. H : ON L : OFF
28 S LEVEL I Signal level input.(E/T type only)
29 A Vdd - A/D power supply(+5V).
30 A VREF - A/D reference voltage(+5V).
31 CLOCK - 32.768kHz oscillator.
32 CLOCK - 32.768kHz oscillator.
33 Vss - Microprocessor power supply(GND).
34 MAIN COLCK - 4.19MHz oscillator.
35 MAIN COLCK - 4.19MHz oscillator.
36 S DATA I/O 16 bit system data.
37 S BUSY I/O 16 bit system busy. H : BUSY L : READY
38 H.P. MUTE O Muting signal input of headphones. L : ON
39 ATT O Attenuator control. L : ON
40 A MUTE O Audio muting signal control. L : ON
41 LOW RELAY O Amplifier low relay control. H : ON L : OFF
42 HI RELAY O Amplifier high relay control. H : ON L : OFF
43 SP RELAY O Speaker relay control.

44,45 NC I Unused.

46 PROTECTION I Detection signal input of protection. H : ON L : OFF
47 REMOCON I Remote control input.
48 IC(VPP)GND - Connected to VSS.
49 CLASS A LED O Control signal output of class A LED. L : ON
50 BIAS A MID O Bias control signal(MID) output.
51 BIAS B HI O Bias control signal(HI) of class A LED.
52 Vdd - Microprocessor power supply(+5V).
53 ENC A I Volume encoder (A) input.
54 ENC B I Volume encoder (B) input.
55 HEAD PHONES I Detection signal input of headphones. H : ON L : OFF

56,57 - O Unused.
58~60 KR2~KR0 I Key return input(KR2~KR0). H : Key ON
61~64 P16~13/KS3~0 O FL segment(6~13)/key scan(KS3~KS0). H : ON
65~70 P12~P7 O FL segment(12~7) control. H : ON

71 VLOAD - FL driver power supply(-30V).

72~77 P6~P1 O FL segment(6~1) control. H : ON

78 NC - Unused.

79,80 9G,8G O FL grid(9G,8G) control.

6

ADJUSTMENT

NO. ITEM

INPUT

SETTINGS

OUTPUT

SETTINGS

TUNER

SETTINGS

ALIGNMENT

POINTS

ALIGN FOR FIG.

1

DISCRIMINATOR

(A)

98.0kHz

1kHz, ±75kHz dev.

60dBµ(ANT input)

Connect a DC

voltmeter

between

Pin 1 and Pin 2

of CN 2.

MONO

98.0MHz

L 31 0V

(a)

L 32 Minimum distortion.

2

DISTORTION

(STEREO)

(C)

98.0MHz

1kHz, ±68.25kHz dev.

Pilot: ±6.75kHz dev.

60dBµ(ANT input)

(B)

AUTO

98.0MHz

IFT (A1) Minimum distortion. (a)

NO. ITEM

INPUT

SETTINGS

OUTPUT

SETTINGS

AMP

SETTINGS

ALIGNMENT

POINTS

ALIGN FOR FIG.

POWER: ON SELECTOR : AUX

1–

B CLASS

IDLE CURRENT

Connect a DC

voltmeter across

CN1(L)
CN2(R)

(X09, A/7)

PURE A : OFF

Volume : 0

VR1(L)

VR2(R)

(X09, A/7)

20mV (b)

SPEAKER
(6 – 16 Ω)

R

L

SUB
WOOFER
PRE OUT

FM75Ω

FM300Ω GND

AM

ANTENA

SYSTEM

CONTROL

R

L

IN IN

CD AUX

REC OUT

PLAY OUT

REC OUT

PLAY OUT

TAPE

MD

Oscilloscope

Distortion meter

AC voltmeter

Dummy antenna

(A)

(B)

(C)

(D)

AG

AG

FM SG

MPX

AG

FM SG

AM SG

(a) (b)

CN1(L)
CN2(R)

Dc voltmeter

20mV

FM SECTION SELECTION :FM

X05-4882-70 (E/T TYPE)

X05-488X(E/T)/486X(M)

No. ITEM INPUT SETTING

OUTPUT

SETTING

TUNER

SETTING

R-SG7/SG7G

ALIGNMENT

POINTS

ALIGN FOR FIG.

(A)

1

TUNED LEVEL

98.0MHz MONO

1 kHz, ±75 kHz dev.

(B)

30dBu ±10 dB (ANT input)

SYSTEM CONNECTIONS

MONO

98.0MHz

VR1

Adjust VR1 and

stop at the point

where EDI

(TUNED) goes ON.

(a)

AUDIO SECTION (X09-496x-xx)

7

A BDCE

PC BOARD (Component side view)

1

2

3

TUNER UNIT (X05-4860-71) : M

4

TUNER UNIT (X05-4882-70) : ET

5

6

7

8

Refer to the schematic diagram for the value of resistors and capacitors.