Kenwood HM-437WM User manual

COMPACT Hi-Fi COMPONENT SYSTEM
RXD-M47WM-H/M47WM-S
LS-M47WM-H/M47WM-S
SERVICE MANUAL
(HM-437WM) © 2005-9 PRINTED IN KOREA
B51-5961-00 (K/K) 592
In compliance with Federal Regulations, following are repro-
duction of labels on, or inside the product relating to laser
product safety.
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.
Caution : No connection of ground line if disassemble
the unit. Please connect the ground line on
rear panel, PCBs, Chassis and some others.
CD cover ass’y *
(F07-)
Phone jack
(E63-1365-08)
Power knob
(K29-8499-08)
Display/Rec. knob
(K29-8501-08)
Search knob
(K29-8503-08)
Cass lid ass’y *
(A53-)
Front cabinet *
(A60-)
Volume knob
(K29-8502-08)
CD/Tuner/Tape knob
(K29-8504-08)
EQ/Bass knob
(K29-8500-08)
.
*Refer to parts list on page 26.

Remote control unit (1)
(A70-1709-08): E type
(A70-1710-08): X type
AM loop antenna (1)
(T90-0908-08)
ANT TERMI CVR
(F07-2029-08)
Batteries (R6/AA) (2)
(–)
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 out-
side 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 can-
not be operated, or shows an erroneous dis-
play) 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 re-
turn the unit to its normal operating condition.
When the power is on and TUNER input is
selected, press and hold down the button
for more than 2 seconds.
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-M47WM/LS-M47WM
2
ACCESSORIES / CAUTIONS
Accessories
Cautions
System configuration
SYSTEM RECEIVER SPEAKER
HM-437WM-H RXD-M47WM-H LS-M47WM-H
HM437WM-S RXD-M47WM-S LS-M47WM-S

RXD-M47WM/LS-M47WM
3
EXTERNAL VIEW
R
L
SPEAKERS
IMPEDANCE:
4Ω
AC ~
FM ANT
AM ANT
Rubber foot
(J02-1563-08)x4
Rear cabinet
(A80-4535-08) AM Antenna
(E40-8089-08)
Speaker terminal
(E70-0196-08)
AC power cord *
(E30-)
*Refer to parts list on page 26.

RXD-M47WM/LS-M47WM
4
DISASSEMBLY FOR REPAIR / BLOCK DIAGRAM
DISASSEMBLY INSTRUCTIONS
LEFT SURFACE RIGHT SURFACE
1
2
3
4
BOTTOM SURFACE BACK SURFACE
LUOKAN 1 LASERLAITE
KLASS 1 LASERAPPARAT
CLASS 1LASER PRODUCT
LASER KLASSE 1
APPAREIL A LASER DE CLASSE 1
MAN UFACTURED:
RISK OF ELECTRIC SHOCK
DO
N
A
CAUTION
DO NOT OPEN
6
5
R
L
SPEAKERS
IMPEDANCE:
4 ¸
A
C~
FMANT
AMANT
10
9
8
7
DETACH REAR CABINET FROM FRONT CABINET MUST BE REMOVED FROM 1 TO 10 SCREWS.
BLOCK DIAGRAM
MCU
U101
U103
M24C16
EEPROM
Q803
8.1V CD SUPPLY
TO: CD-PCB
TO: U601 SC7313S
TO: U301 AN7312E
TO: U201 TA2104AFN G
CPU
TO: U260TC9257F
U802 7812
12V
LCD
KEYMAP
REMOTE
SENSE
MUTE CUT Q801 Q802
U601
SC7313S
AUDIO SIGNAL SOURCE SELECTOR
EQ MODE SEIECTOR
VOLUME CONTROL
RDS
U250 SC6579A
PLL CONTROL
FUNCTION CONTROL
U260 TC9257F G
TAPE PRE. AMP.
U301 AN7312E
ELECTRONICE
SWITCH
TRANSISTORS
LOGIC
CASS DECK
W991S-107G
RADIO SECTION
U201 SA2104S
IC601
CD DSP
TC94A14FA
IC602
CD RF
TA2157FN
CD MACHINE
TCP11TK2PX
IC604
MP3/WMA DECODE
TC94A34FG
IC603
CD MOTOR DRIVER
MM1669XH
IC607
LPF
SC1308LS
IC605
DAC
PT8211
FM ANT (PIG TAIL)
AM ANT
SOCKET
AUDIO AMP.
U801
BA5415A
D905-D908
F901 3.15A
14.5V MAIN SUPPLY
MAIN TRANSFORMER
T902
STANDBY
TRANSFORMER
D901-D904
DC 5V
CN801
32 ohm
HEADPHONE
JACK
REMOTE CONTROLLED
POWER SECTION
RY901
SDT-S-105LMR
POWER RELAY
4 ohm IMPEDANCE
AUDIO OUT
CD SECTION
PLAY OUT OF TAPE
AC PLUG
REC IN

RXD-M47WM/LS-M47WM
5
SAFETY
Important Note!!! Do the following safety checks after servicing this unit.
1. Remove all the externally connected test equipment and wires before testing the unit.
2. Use the safety test circuit as shown below.
3. Plug the power cord or unit to be tested into the test receptacle.
4. Switch the unit being tested to ON or PLAY.
5. Connect external jack/terminal contact VTVM across a 1k resistor in the test circuit. Set the meter to a
high (150V AC) scale to avoid meter damage and then touch the points with the test probe.
If the meter reading indicates less than 3 volts on all test points, set the meter to a low (3V AC) scale
and repeat the test.
6. Any reading greater than 0.2 volt indicates a potential shock hazard. If this occurs, determine the
cause of the leakage, correct the problem, and repeat the safety test.

RXD-M47WM/LS-M47WM
6
ADJUSTMENT
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.

RXD-M47WM/LS-M47WM
7
ADJUSTMENT
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

RXD-M47WM/LS-M47WM
8
ADJUSTMENT
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 100 kHz ±0.5 kHz.
4. Confirm the record head voltage equal to: 4-8V.

RXD-M47WM/LS-M47WM
9
ADJUSTMENT
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

RXD-M47WM/LS-M47WM
10
ADJUSTMENT
FM Alignment:
Figure 6. FM Band Frequency Coverage Alignment
Connect FM S/G to ANT inputs (mod 1 kHz 22.5kHz dev.)
Step S/G Frequency Dial Setting Indicator Adjust Remarks
1 87.5 MHz Low end Connect DC voltage
meter to test point Vt
and ground
L203 Adjust until Vt equal to:
2.5 ±0.05V
2 108 MHz High end Same as step 1 Confirm Vt: 7-9V
3 90.1 MHz 90.1 MHz Connect oscilloscope
or VT/VM to speaker
jack
L204 Adjust until Maximum
output
4 106.1 MHz 106.1 MHz Same as step 3 VC202 Adjust until maximum
output
5 Repeat steps 3 and 4 to minimize tracking error.
FM GENERATOR
DUMMY
ANTENNA
TP1
TEST UNIT
OSCILLOSCOPE
DUMMY LOAD
VTVM
R-OUT
L-OUT
GND
Figure 7. FM Band/Tracking
GROUND METER
Vt DC
TEST UNIT