Akai DDV-805 Service Manual
Car Multimedia Centre
DDV805
CONTENTS
Page
Disassembly Instructions ..................................................................................................................................... 3
Disassembly Diagram.......................................................................................................................................... 4
Disassembly Instructions˄TV7020˅ ................................................................................................................. 5
Disassembly Diagram˄TV7020˅...................................................................................................................... 6
Operation Check.................................................................................................................................................. 7
Block Diagram ..................................................................................................................................................... 8
Alignment Locations ............................................................................................................................................9
Alignment Procedures .......................................................................................................................................10
Printed Circuit Board.......................................................................................................................................... 11
Exploded View (Display).................................................................................................................................... 31
Exploded View Part List (Display)......................................................................................................................32
Exploded View (Unit) ......................................................................................................................................... 34
Exploded View Parts List (Unit) ......................................................................................................................... 35
Exploded View (TV7021) ................................................................................................................................... 37
Exploded View Part List (TV7021)..................................................................................................................... 38
Exploded View (Deck) .......................................................................................................................................39
Exploded View Part List (Deck) ......................................................................................................................... 40
Schematic Diagram ...........................................................................................................................................42
Electrical Parts List ............................................................................................................................................ 54
Specifications..................................................................................................................................................... 74
2
DISASSEMBLY INSTRUCTIONS (UNIT)
1ˊUsing the unlock key that came with the unit or a similar tool, unlock the Mounting Box and remove toward
the rear of the unit.
2ˊTake out the Ring and remove two screws (A) from each side of the base then remove the Base.
3ˊRemove two screws (B) located on the Main Board left side of the side bracket.
Remove two screws (C) located on the Main Board Right side of the side bracket.
4ˊRemove two screws (F) located on the under of the deck front Bracket.
Remove two screws (G) located on the front of the deck front bracket then remove the Deck Bottom
Bracket.
5ˊRemove two screw (H) and the Wire Clip.
6ˊRemove the screws (I) from on the Rear of the under side bracket then remove heat sink.
Remove the screws (J) from on the Rear of the top side bracket then remove heat sink.
7ˊRemove two screws (K) from on the back of the Rear-right Cabinet then remove the DC FAN 12V and
The Fan Cover.
3
DISASSEMBLY DIAGRAM (UNIT)
4
DISASSEMBLY INSTRUCTIONS (TV7020)
1. Remove two screws (A) from each of the Top Cover then remove the Top Cover.
2. Remove four screws (B) from on the main board then remove the Bottom Cover and Main Board.
5
DISASSEMBLY DIAGRAM (TV7020)
6
OPERATION CHECK
GENERAL SPECIFICATIONS OF SIGNAL
Standard frequency
Signal output
Modulation
FM
MW
FM
MW
MW
FM Stereo
98.1 MHz (87.5, 108.0 MHz)
1000 kHz (522, 1620 kHz)
1 mV
5 mV
400 Hz 30% MOD.
1 kHz 75 kHz DEV.
46% for L only or R
only pilot level 8%.
AF output level FM/MW
Power source voltage DC 14.4V (Backup voltage is the same as this)
AF load impedance 4 ohm pure resistance
Balance Center position of level
Tone Center position.
The signal strength read in this section is voltage on the antenna.
Test Diagram
2-SPEAKER
FRONT
SPK.
4-SPEAKER
RL.
SPR.
FL.
SPK.
4-SPEAKER
RR.
SPK.
FR.
SPE.
2-SPEAKER
FRONT
SPK.
ACC (DV14.4V)
BACK UP (14.4V)
GROUND
DISTORTION
METER
VTVM
VTVM
DUMMY
ANTANNA
AM SG
MAIN UNIT
FM SG
POWER ANTANNA
ANT
MPX
STEREOS
MODULATOR
7
BLOCK DIAGRAM (UNIT)
8
MITSUMI TUNER
ALIGNMENT LOCATIONS
9
ALIGNMENT PROCEDURES
z
z
z
z
z
FM ADJUSTMENT
Equipment Required
AM IF/RF signal generator
Solid-state voltmeter (SSVM)
Regulated DC power supply
2-CH voltmeter
Distortion meter
FM Alignment Using FM Signal Generator
Note: Press the radio power switch to on the radio. Signal generator output must be kept as low as possible
to avoid overload and clipping.
Step Generator
Coupling
Stereo
Separation
FM SNC
Adjustment
Stop
SENS.
Signal
Generator
to antenna
receptacle
98.1 MHz
Dev. 75 kHz
L+R=90 %
Int. 1 kHz
60dBμV output
Signal Generator
to antenna
receptacle
Generator Display
98.1 MHz
Int. 1 kHz
Dev. 75 kHz
L+R = 90 %
pilot = 10 %
98.1 MHz
@ 40 dBμ
98.1 MHz
Mod. 1kHz
Dev 75kHz
1000 kHz
Mod. 1kHz
Mod 30%
98.1 MHz VR3
98.1 MHz VR2 Stereo Separation
98.1 MHz VR4
1000 kHz VR1
Adjustment Remarks
Setting
Adjust AF
output power
at maximum
separating
more than 30 dB
25 dB (±5 dB)
Adjust AF to
stop station.
Note: The tuner module is well-adjust and adjustment is not recommended.
10
MAIN BOARD
PRINTED CIRCUIT BOARDS
TOP VIEW
11
MAIN BOARD
BOTTOM VIEW
12
KEY BOARD
TOP VIEW
13
KEY BOARD
BOTTOM VIEW
14
MOTOR CONTROL BOARD
TOP VIEW
15
MOTOR CONTROL BOARD
BOTTOM VIEW
16
REMOTE BOARD
TOP VIEW
17
REMOTE BOARD
BOTTOM VIEW
18
LCD BOARD
TOP VIEW
19
LCD BOARD
BOTTOM VIEW
20
SWITCH BOARD
TOP VIEW
21
SWITCH BOARD
BOTTOM VIEW
22
SERVO BOARD
TOP VIEW
23
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