Akai AC-R127-MMC Service Manual
CD/MP3–RECIVER
Model:
ACR127MMC
SERVICE MANUAL
www.akai.ru
CONTENTS
Page
Disassembly Instructions....................................................................................................................................... 3
Disassembly Diagram............................................................................................................................................ 4
Operation Check.................................................................................................................................................... 5
Block Diagram ....................................................................................................................................................... 6
Alignment Locations .............................................................................................................................................. 7
Alignment Procedures ........................................................................................................................................... 8
Printed Circuit Boards............................................................................................................................................ 9
Exploded Views (Panel) ...................................................................................................................................... 18
Exploded View Parts Lists (Panel) ...................................................................................................................... 19
Exploded Views (Cabinet) ................................................................................................................................... 20
Exploded View Parts Lists (Cabinet) ................................................................................................................... 21
Exploded Views (Deck) ....................................................................................................................................... 23
Exploded View Parts Lists (Deck) ....................................................................................................................... 24
Schematic Diagram ............................................................................................................................................. 26
Electrical Parts List .............................................................................................................................................. 29
Specifications....................................................................................................................................................... 36
2
DISASSEMBLY INSTRUCTIONS
1. Using the unlock key that came with the unit or a similar tool, unlock the Mounting Box and remove toward
the rear of the unit.
2. Remove two screws (A) located on the rear of the top cabinet then remove the Top Cabinet.
3. Remove two screws (B) located on the rear of the bottom cabinet then remove the Bottom Cabinet.
4. Take out the Front Panel and the Ring.
Remove the screws (C) from on the front side of the Base.
5. Remove two screws (D) from on the right side of the side bracket.
Remove two screws (E) from on the left side of the side bracket.
6. Remove two screws (F) from under the deck front bracket then remove the Deck Front Bracket.
Remove two screws (G) from under the deck rear bracket then remove the Deck Rear Bracket and the
Deck.
7. Remove the screw (H) from on the right side of the side bracket then remove the IC Bracket.
8. Remove two screws (I) from on the left side of the heat sink then remove the Spring Sheet.
9. Remove three screws (J) from on the left side of the heat sink then remove the Heat Sink.
10. Remove the screw (K) from on the back of the side bracket and remove two screws (L) from on the main
board then remove the Heat Sink (7809/DB435).
10. Remove two screws (M) from on the back of the side bracket then remove Wire Clip.
11. Remove two screws (N) from each side of the base then remove the Base.
12. Remove three screws (O) from under the main board then remove the Side Bracket and the Main Board.
13. Remove two screws (P) from under the main board then remove the two SD PCB Bracket an the SD PCB
Board.
3
DISASSEMBLY DIAGRAM
4
OPERATION CHECK
GENERAL SPECIFICATIONS OF SIGNAL
Standard frequency
Signal output
Modulation
FM
MW
LW
FM
MW
LW
MW
FM Stereo
AF output level FM/MW/LW
Power source voltage DC 14.0V (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
98.1 MHz (87.5, 108 MHz)
1000 kHz (522, 1620 kHz)
200 kHz (144, 288 kHz)
1mV
5 mV
5 mV
400 Hz 30% MOD.
1 kHz 75kHz DEV.
46% for L only or
R only pilot level 8%
RR.
SPK.
FR.
SPE.
2-SPEAKER
FRONT
SPK.
ACC (DV14.4V)
BACK UP (14.4V)
GROUND
POWER ANTANNA
MAIN UNIT
ANT
DISTORTION
METER
VTVM
VTVM
DUMMY
ANTANNA
AM SG
FM SG
MPX
STEREOS
MODULATOR
5
BLOCK DIAGRAM
6
FM TUNER BOARD
ALIGNMENT LOCATIONS
7
ALIGNMENT PROCEDURES
FM ADJUSTMENT
Equipment Required
z AM IF/RF signal generator
z Solid-state voltmeter (SSVM)
z Regulated DC power supply
z 2-CH voltmeter
z 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.
Note: The tuner module is well-adjust and adjustment is not recommended.
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
98.1 MHz VR1
98.1 MHz VR2
98.1 MHz
Setting
Adjustment Remarks
Adjust AF
output power
at maximum
separating
more than 30 dB
Stereo Separation
25 dB (±5 dB)
VR3
Adjust AF to
stop station.
8
MAIN BOARD
PRINTED CIRCUIT BOARDS
TOP VIEW
9
MAIN BOARD
BOTTOM VIEW
10
KEY BOARD
TOP VIEW
11
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