Components Description - Kenwood kac-8403 Service Manual

PREAMPLIFIER UNIT (X08-4200-12)
Ref. No. Application / Function
IC1 (2/2) ARch reversal buffer
IC1 (1/2) BRch reversal buffer
IC4 Bch HPF
IC5 Ach HPF
IC6 Bch LPF
IC7,8 Bch Bass boost filter
AUDIO UNIT (X09-5840-12)
Ref. No. Application / Function
IC1,2 Input isolation amp
IC4 Switching regulator controller
For temperature protection and -3dB attenuator
IC6
comparators
Q1 For +15.6V AVR
Q2 For -15.6V AVR
Q4,5,7,8 DC/DC converter FET
Q9~12 For FET driving
Q13,14 FET drive low start SW
Q201~210 For ACH voltage amplifying step differential amplifying
Q211 For temperature compensation bias
Q212 For ACH voltage amplifying step differential amplifying
Q213 For temperature compensation bias
Q214~219 For ACH voltage amplifying step differential amplifying
Q220 For ACH final current amplifying
No. ITEM
IDLE
1
CURRENT

COMPONENTS DESCRIPTION

ADJUSTMENT
ALIGNMENT POINT
VR1 (ALch)
Connect a DC voltmeter
VR2 (ARch)
between check land
VR3 (BLch)
(Refer to PC BOARD)
VR4 (BRch)
Ref. No.
Q221 For ACH voltage amplifying step differential amplifying
Q222,223 For ACH final current amplifying
Q225 For ACH final current amplifying
Q241,242 Mute
Q280 -3dB Attenuator circuit
Q282 -3dB Attenuator circuit
Q401~410 For BCH voltage amplifying step differential amplifying
Q411,412 For temperature compensation bias
Q415~422 For BCH voltage amplifying step differential amplifying
Q423~426 For BCH final current amplifying
Q443,444 Mute
Q481,482 -3dB Attenuator circuit
Q601 For shock noise prevention
Q602 P-CON ON/OFF processing
Q603 Mute driver
Q604 +B SW
Q605 P-CON ON/OFF processing
Q606 For BU excess voltage detection
Q607 FAN +B, Always ON
For excess current detection and excess current
Q610
protection
Q611~614 For output DC abnormal voltage detection
Q615~618 For shock noise prevention
Q619,620 Logo LED power supply
Q621~628 For temperature detection
METHOD ALIGN FOR
2.5mV
KAC-8403
Application / Function
NOTE
After Power on
5 minutes
3