Components Description - Kenwood KAC-8402 Service Manual

QQ
3 7 63 1515 0
PREAMPLIFIER UNIT (X08-4200-10)
Ref. No.
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 (X09-5840-1x)
Ref. No.
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
TE
Q3~8 DC/DC converter FET
L 13942296513
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
No. ITEM
IDLE
1
CURRENT
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COMPONENTS DESCRIPTION

Application / Function
Application / Function
ADJUSTMENT
ALIGNMENT POINT
VR1 (ALch)
VR2 (ARch)
VR3 (BLch)
VR4 (BRch)
x ao u163
y
i
KAC-8402/8452
2 9
8
Ref. No.
Q220 For ACH final current amplifying
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
Q Q
Q605 P-CON ON/OFF processing
3 6 7 1 3 1 5
Q606 For BU excess voltage detection
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
Connect a DC voltmeter
between check land
(Refer to PC BOARD)
co
.
9 4 2 8
Application / Function
0 5 8 2 9 9 4 2 8
ALIGN FOR NOTE
After Power on
2.5mV
m
5 minutes
9 9
9 9
3