Kenwood RXDM-47-MP Service manual
COMPACT Hi-Fi COMPONENT SYSTEM
70%
RXD-M47MP
SERVICE MANUAL
(HM-437MP)
CD cover ass’y
(F07-2030-08)
Phone jack
(E63-1365-08)
Power knob
(K29-8426-08)
© 2004-10 PRINTED IN KOREA
B51-5934-00 (K/K) 715
EQ/Bass knob
(K29-8427-08)
CD/Tuner/Tape knob
(K29-8431-08)
Display/Rec. knob
(K29-8428-08)
Search knob
(K29-8430-08)
Cass lid ass’y
(A53-2455-08)
In compliance with Federal Regulations, following are reproduction of labels on, or inside the product relating to laser
product safety.
Caution : No connection of ground line if disassemble
the unit. Please connect the ground line on
rear panel, PCBs, Chassis and some others.
Volume knob
(K29-8429-08)
Front cabinet
(A60-2427-08)
KENWOOD Corp. certifies this equipment conforms to DHHS
Regulations No.21 CFR 1040. 10, Chapter 1, subchapter J.
DANGER : Laser radiation when open and interlock defeated.
AVOID DIRECT EXPOSURE TO BEAM.
Remote control unit (1)
(A70-1692-08)
AM loop antenna (1)
(T90-0908-08)
ANT TERMI CVR
(F07-2029-08)
Batteries (R6/AA) (2)
(–)
Plug in the AC power cord to the wall outlet, and within 5 seconds, press and hold
down the button and press CD button.
The marking of products using lasers
The marking this product has been classified as Class 1. It
means that there is no danger of hazardous radiation outside the product.
Location: Bottom
CLASS 1 LASER PRODUCT
LASER KLASSE 1
APPAREIL A LASER DE CLASSE 1
LUOKAN 1 LASERLAITE
KLASS 1 LASERAPPARAT
Resetting the Microcomputer
The microcomputer may malfunction (unit cannot be operated, or shows an erroneous display)if the power cord is unplugged while the
power is ON, or due to some other external
factor. If this happens, execute the following
procedure to reset the microcomputer and return the unit to its normal operating condition.
Please note that resetting the microcomputer
will clear the contents of the memory and
return the unit to the state it was in when it
left the factory.
RXD-M47MP
CONTENTS / ACCESSORIES / CAUTIONS
Contents
CONTENTS / ACCESSORIES / CAUTIONS...............2
EXTERNAL VIEW ........................................................3
ADJUSTMENT .............................................................4
PC BOARD ..................................................................9
Accessories
SCHEMATIC DIAGRAM ............................................13
EXPLODED VIEW .....................................................19
SPECIFICATIONS..................................BACK COVER
System configuration
SYSTEM RECEIVER SPEAKER
HM-437MP RXD-M47MP LS-M47
Cautions
2
Rear cabinet
(A80-4503-08)
RXD-M47MP
EXTERNAL VIEW
Antenna cover
(F07-2029-08)
Speaker terminal
(E70-0196-08)
AC power cord
(E30-7343-08)
3
RXD-M47MP
SERVICE ADJUSTMENT
Lubrication
The mechanical parts are factory coated with a thin coat of light grease and should not require further
lubrication. If a light grease is applied, be careful not to get any grease on the play/record head or erase
head, hubs, pulleys, tapes reels, drive belts, or switches. Use a good lubricant such as Silicon Lube G322L
or Lubricate.
Service Check
Before aligning the mechanism, wipe off any accumulated dirt with denatured alcohol. Wipe around parts
where the tape contacts and around all rotating parts. Drive belts are specially processed. Do not clean
them with alcohol.
Mechanical Torque
Use a cassette type torque gauge and check the tape mechanism.
Take-up torque 35 to 70 g-cm
Rewind torque 50 g-cm min.
Fast forward torque 50 g-cm min.
Pinch Wheel Pressure
No adjustment to the pinch roller spring is necessary. It should be sufficient to give at least 40 g-cm pull
force.
Tape Head Servicing
Each time the unit is serviced, the face of all heads should be thoroughly cleaned with denatured alcohol or
commercial head cleaning solution. The playback head should be demagnetized with a commercial
demagnetizer. Accumulation of tape oxide during normal operations can cause problems, including loss of
high frequencies and wow and flutter.
Erase Head
The erase head is properly aligned when the tape rides directly between the tape guide on the head without
crinkling the tape.
ADJUSTMENT
4
RXD-M47MP
Play/Record and Playback Head Azimuth Adjustment
To adjust the play/record and playback head azimuth screw:
1. Connect two (2) VTVMs and a dual trace scope to the stereo headphone jack (as shown) with a 32
ohm dummy load. (See Figure 1.)
VTVM VTVM
DUMMY LOAD
JK801
SCOPE
CH1
CH2
Figure 1. Azimuth Adjustment
2. Insert a 10 kHz test tape (Teac MTT-1141V or Equivalent) into the tape mechanism and play it back.
3. While playing back the test tape, slowly turn the azimuth adjusting screw until the amplitude of both
channel output waveforms is maximum and in phase. (See Figure 2.)
4. Secure the azimuth screw in place with glue or paint after making the adjustment.
Figure 2. Head Output Signal
ADJUSTMENT
5
RXD-M47MP
Tape Speed Adjustment
1. Set the function switch to TAPE.
2. Connect a frequency counter with a 32 ohm dummy load to the stereo headphone jack. (See Figure 3.)
FREQUENCY COUNTER
DUMMY LOAD
JK801
Figure 3. Tape Speed Adjustment
3. Insert and play back a 3 kHz test tape (Teac MTT-111 or Equivalent) into the tape mechanism.
4. Insert an insulated alignment tool and adjust the tape speed potentiometer (MOTOR) until the
frequency counter indicates 2940 Hz to 3090 Hz.
Bias Oscillator Frequency and Level Adjustment
1. Set the function switch to TAPE and the record and play tape mechanism to RECORD.
2. Connect a VTVM and frequency counter to test point R/P HEAD.
3. Adjust bias oscillator coil T360 until the frequency counter indicates 81 kHz ± 0.5 kHz.
4. Confirm the record head voltage equal to: 6-12V.
5. Confirm the erase head voltage equal to: 15-24V.
ADJUSTMENT
6
RXD-M47MP
TUNER ALIGNMENT PROCEDURE
Equipment needed:
1. AM Signal generator
2. FM Signal generator
3. DC Voltage meter
4. Oscilloscope
5. Output meter (VTVM)
AM Alignment
Step S/G Frequency Dial Setting Indicator Adjust Remarks
1 450 kHz (1 kHz 30% mod.) 612 kHz Connect
oscilloscope or
VTVM to speaker
jack
T201 Adjust until
maximum
output
2 531 kHz (1 kHz 30% mod.) Low end Connect DC voltage
meter to test point Vt
and ground
T202 Adjust until
Vt equal to
1.5 ± 0.05V
3 1602 kHz (1 kHz 30% mod.) High end Same as step 2 Confirm Vt:
6.5~8.5V
4 612 kHz (1 kHz 30% mod.) 612 kHz
Same as step 1 T203 Maximum output
5 1404 kHz (1 kHz 30% mod.) 1404 kHz Same as step 1 VC201 Maximum output
6 Repeat steps 4 and 5 to minimize tracking error
7 999 kHz
(1 kHz 30%mod.)
999 kHz
Same as step 1 Offset is less than
6 dB.
60 cm
AM SIGNAL GENERATOR
AM LOOP ANT
AM LOOP
ANTENNA
DUMMY LOAD
TEST UNIT
VTVM
R-OUT
L-OUT
GND
Figure 4. AM IF/RF Tracking
TEST UNIT
GROUND METER
Figure 5. AM Band Frequency Coverage Alignment
Vt DC
ADJUSTMENT
7
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