Kenwood R-SG7 Service Manual Download Page 3

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R-SG7/SG7G

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.

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 micro-
computer detects the signal and enters the stop state.

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