Component Description - Kenwood KRC-279RA Service Manual

SYNTHESIZER UNIT (X14-656x-xx)
REF No. FUNCTION
IC1 SYSTEM µ-COM
IC2 E-VOLUME
IC3 MUTE LOGIC
IC4 POWER AMPLIFIER
IC5 EQUALIZER AMPLIFIER
IC6 RESET
IC7 RDS DECODER
Q49 ACC DETECTION SW
Q50 BACK-UP DETECTION SW
Q51,52 BACK-UP 5V DRIVER
Q53 P.ON 5V SW
Q54,55 8V SW
Q56,57 8V DRIVER
Q58,59 ILLUMI +B SW
Q60,61 ILLUMI +B DRIVER
Q150 E-VOL MUTE SW
Q151 SVR FORCED DISCHARGE SW
Q153 PRE OUT MUTE SW
Q201 FM +B SW
Q203 AM +B SW
Q260 MOTOR +B SW
Q261 MOTOR +B DRIVER
Q301 CD-CH RESET SW
Q320 PANEL 5V SW
Q350 P.CON DRIVER SW
Q351 P.CON PROTECTION SW
Q352 P.CON PROTECTION INHIBIT SW Inhibits the protection SW in a moment during the P.CON on.
Q353 P.CON DRIVER SW
Q450,451 PRE OUT MUTE SW
Q500 AUDIO OUTPUT BUFFER
Q501,502 AFC TIME CONSTANT SW
Q503 NOISE BUFFER
KRC-15R,179R,25R,279R,281R

COMPONENT DESCRIPTION

Controls the unit.
Controls the volume and selects source.
Controls the mute output.
For the speaker output.
For the cassette tape's signal.
Resets the power.
Decodes the radio data.
Outputs "H" during the ACC off.
Outputs "H" when the back-up voltage is under 9.2V.
Works when back-up current exists.
Works during the power on.
Works during the power on.
Works during the power on.
Works during the power on.
Works during the power on.
Works when the back-up current is detected
or the changer mute works or system µ-com mute works.
Works when the amplifier mute works.
Works when the back-up current is detected
or the changer mute works or system µ-com mute works.
Works during FM mode.
Works during AM mode.
Works during the tape mode.
Works when Q206 works.
Works when the power is reset and the reset SW works.
Works when the back-up current exists and the panel
is attached on the unit.
Does not work during the power off and the ALL OFF.
Works when the P.CON is short-circuited on the GND.
Does not work during the power off and the ALL OFF.
Works when the back-up current is detected
or the changer mute works or system µ-com mute works.
For RDS decoder.
Works during receiving FM signal.
For noise level detection.
OPERATION
3