Akai ACR-48MP User manual

SERVICE MANUAL
Models:
ACR-48MP
CD/MP3/USB/RDS–RECIVER
www.akai.ru

2
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).......................................................................................................................................15
Exploded View Parts Lists (Panel) ......................................................................................................................16
Exploded Views (Cabinet) ...................................................................................................................................17
Exploded View Parts Lists (Cabinet)...................................................................................................................18
Exploded Views (Deck)........................................................................................................................................19
Exploded View Parts Lists (Deck) .......................................................................................................................20
Schematic Diagram .............................................................................................................................................22
Electrical Parts List ..............................................................................................................................................25
Specifications.......................................................................................................................................................32

3
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 two screws (C) from on the front side of the Base.
5. Remove two screws (D) from on the right side of the U bracket.
Remove two screws (E) from on the left side of the U 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.
7. Remove two screws (H) from on the left side of the heat sink then remove the Spring Sheet.
8. Remove five screws (I) from on the left side of the heat sink then remove the Heat Sink.
9. Remove the screw (J) from on the back of the U bracket and remove two screws (K) from on the main board
then remove the Heat Sink (7809/DB435).
10. Remove two screws (L) from on the back of the U bracket then remove Wire Clip.
11. Remove two screws (M) from each side of the base then remove the Base.
12. Remove three screws (N) from under the main board then remove the U Bracket and the Main Board.

4
DISASSEMBLY DIAGRAM

5
OPERATION CHECK
GENERAL SPECIFICATIONS OF SIGNAL
Standard frequency
Signal output
Modulation
FM
MW
FM
MW
MW
FM Stereo
98.1 MHz (65.0, 74.0MHz) (87.5, 107.9 MHz)
1000 kHz (530, 1710 kHz)
1mV
5 mV
400 Hz 30% MOD.
1 kHz 75kHz DEV.
46% for L only or
Ronlypilotlevel8%
AF output level FM/MW
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.
TestDiagram
4-SPEAKER
VTVM
DISTORTION
METER
2-SPEAKER
FRONT
SPK.
SPK.
FL.
RL.
SPR.
MAIN UNIT
AM SG
VTVM ANTANNA
DUMMY
FM SG
MODULATOR
STEREOS
MPX
ANT
FRONT
SPK.
SPE.
FR.
RR.
4-SPEAKER
SPK.
2-SPEAKER
POWER ANTANNA
ACC (DV14.4V)
GROUND
BACK UP (14.4V)

6
BLOCK DIAGRAM

7
ALIGNMENT LOCATIONS
MITSUMI TUNER

8
ALIGNMENT PROCEDURES
FM ADJUSTMENT
Equipment Required
zAM IF/RF signal generator
zSolid-state voltmeter (SSVM)
zRegulated DC power supply
z2-CH voltmeter
zDistortion 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 Generator Display Setting Adjustment Remarks
Stereo
Separation Signal Generator
to antenna
receptacle
98.1 MHz
Int. 1 kHz
Dev. 75 kHz
L+R = 90 %
pilot = 10 %
98.1 MHz VR1 Adjust AF output power
at maximum
separating
more than 30 dB
FM SNC
Adjustment 98.1 MHz Dev. 75 kHz
L+R=90 %
Int. 1 kHz
60dBµV output
98.1 MHz
@ 40 dBµ
98.1 MHz VR2 Stereo Separation
25 dB (±5 dB)
Stop
SENS. Signal Generator to antenna
receptacle
98.1 MHz
Mod. 1kHz
Dev 75kHz
98.1 MHz VR3 Adjust AF to stop station.
Note: The tuner module is well-adjust and adjustment is not recommended.

9
PRINTED CIRCUIT BOARDS
MAIN BOARD
TOP VIEW

10
MAIN BOARD
BOTTOM VIEW