Component Description - Kenwood KDC-V7521/Y Service Manual

SWITCH UNIT (X16-154X-XX, X16-1892-70)
Ref.No. Component name
IC1 LC75808W
IC2 RS-171
IC3 M62333FP
Q1 DTA114EUA or KRA302
Q3 2SC4081
Q4 2SC4081
Q5 2SC4081
Q6 DTA114EUA or KRA302
Q50-55 UMX2N
Q62 2SC4081
Q63 2SC4081
Q64 2SC4081
ELECTRIC UNIT (X25-9392-7X, X25-8762-72)
Ref.No. Component name
IC1 UPD703033GC139
IC2 TDA7407D
IC3 M5237ML
IC4 TA8273H
HD74HC02FP
IC8 or TC74HC02AF
or 74VHC02SJ
IC14 TDA7479D
IC15 LB1930M
IC16 S-80837ANNP
Q1 2SB1548 (P)
Q2 2SC4081 or 2SD1819A
Q3 2SA1576A or 2SB1218A
Q4 2SB1548 (P)
Q5 DTC144EUA or UN5213
Q6 DTA124EUA or KRA303
Q7 DTA124EUA or KRA303
Q8 DTC144EUA or UN5213

COMPONENT DESCRIPTION

Application/Function
LCD driver with key matrix
Remote sensor IC
D/A converter
Key permission SW
Red LED SW
Green LED SW
VLCD AVR
REMO SW
Constant current driver
Buffer
Buffer
Buffer
Application/Function
System MI-COM.
E. VOL & N.C. MPX IC
AVR IC
Power IC
Mute logic
RDS decoder
Motor driver IC
Reset IC
BU 5V AVR
SW 5V
A8V AVR
A8V AVR SW
SW14V SW
KDC-V7521/Y
Operation/Condition/Compatibility
The brightness control of red, green and blue colour
For the key scanning start and the key detection SW
When a base goes Hi, RED LEDs are turned on.
When a base goes Hi, GREEN LEDs are turned on.
For LCD driver IC
While a base goes Lo, PAN 5V is supplied to the
Remote sensor IC.
The current control of red, green and blue LEDs
for the variable illumination
The control voltage of the constant current driver
for red colour
The control voltage of the constant current driver
for green colour
The control voltage of the constant current driver
for blue colour
Operation/Condition/Compatibility
IC is combined with Q4, and it works as the error
detection, the driver.
2-input NOR x 4
For SRM mechanism drive
When BU 5V voltage is less than 3.7V, IC outputs Lo.
While BACKUP is applied, AVR outputs +5V.
Q1 and Q2 are inverted Darlington connection.
While a base goes Lo, SW 5V is supplied to the
microprocessor peripheral circuits.
Q4 is combined with IC3, and it outputs +8.3V.
A8V AVR ON/OFF control
While Q5's base goes Hi, Q6 is turned on, and
A8V AVR is working.
A8V AVR and SERVO +B AVR ON/OFF control
While Q8's base goes Hi, Q7 is turned on, A8V
AVR and SERVO +B AVR are working.
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