Marantz MR2020 User manual

system MR2020 / Layla 4822 725 51183
First Issue 1999.01
298J855010 MIT
Printed in Japan
Service
Manual
R
Please use this service manual with referring to the user guide ( D.F.U. ) without fail.
74 MR2020 /2G (Layla)
MR2020 F,K,KK,U
CD/Tuner System
TABLE OF CONTENTS
SECTION PAGE
MR2021 (CD/Tuner Amplifier)
1 TECHNICAL SPECIFICATIONS ............................................................................................................. 1-1
2-1 HOW TO DISASSEMBLE ....................................................................................................................... 2-1
2-2 REPAIR INTRODUCTION ...................................................................................................................... 2-6
2-3 EXPLANATION OF CIRCUITS ............................................................................................................... 2-6
3 SERVICE MODE ..................................................................................................................................... 3-1
4-1 BLOCK DIAGRAM .................................................................................................................................. 4-1
4-2 AM STEREO ADJ.(F ONLY) ................................................................................................................... 4-1
4-3 MICROPROCESSOR DATA ................................................................................................................... 4-1
5 WIRING DIAGRAM ................................................................................................................................. 5-1
6 SCHEMATIC DIAGRAM AND PARTS LOCATION................................................................................. 6-1
7B TUNER BOARD ECO5 .........................................................................................................................7B-1
7D TUNER 95 BOARD .............................................................................................................................. 7D-1
8 CD NAMI 8 BOARD................................................................................................................................. 8-1
9 EXPLODED VIEW AND PARTS LIST..................................................................................................... 9-1
10 ELECTRICAL PARTS LIST ................................................................................................................... 10-1
LS2021 ( Speaker System )
1 EXPLODED VIEW AND PARTS LIST.................................................................................................... 1-1
CAUTION
The System MR2020 (Layla) combines MR2021 (CD/Tuner Amplifier) with LS2021 (Speaker System).

MARANTZ DESIGN AND SERVICE
Using superior design and selected high grade components, MARANTZ company has created the ultimate in stereo sound.
Only original MARANTZ parts can insure that your MARANTZ product will continue to perform to the specifications for which
it is famous.
Parts for your MARANTZ equipment are generally available to our National Marantz Subsidiary or Agent.
ORDERING PARTS :
Parts can be ordered either by mail or by Fax.. In both cases, the correct part number has to be specified.
The following information must be supplied to eliminate delays in processing your order :
1. Complete address
2. Complete part numbers and quantities required
3. Description of parts
4. Model number for which part is required
5.Way of shipment
6. Signature : any order form or Fax.must be signed, otherwise such part order will be considered as null and void.
MARANTZ AMERICA, INC.
440 MEDINAH ROAD
ROSELLE, ILLINOIS 60172
USA
PHONE : 630 - 307 - 3100
FAX : 630 - 307 - 2687
LENBROOK INDUSTRIES LIMITED
633 GRANITE COURT,
PICKERING, ONTARIO L1W 3K1
CANADA
PHONE : 905 - 831 - 6333
FAX : 905 - 831 - 6936
MARANTZ EUROPE B.V.
P.O.BOX 80002
BUILDING SFF2
5600 JB EINDHOVEN
THE NETHERLANDS
PHONE : +31 - 40 - 2732241
FAX : +31 - 40 - 2735578
SUPERSCOPE TECHNOLOGIES, INC.
MARANTZ PROFESSIONAL PRODUCTS
2640 WHITE OAK CIRCLE, SUITE A
AURORA, ILLINOIS 60504 USA
PHONE : 630 - 820 - 4800
FAX : 630 - 820 - 8103
TC ELECTRONICS CANADA LTD.
540 FIRING AVE.
BAIE D’URFÉ, QUEBEC H9X 3T2
CANADA
PHONE : 514 - 457 - 4044
FAX : 514 - 457 - 5524
MK ENTERPRISES LTD.
2F SHINHAN BLDG., 247-17 SEOKYO-DONG
MAPO-KU, SEOUL
KOREA
PHONE : +82 - 2 - 323 - 2155
FAX : +31 - 2 - 323 - 2154
MARANTZ BRAZIL
CAIXA POSTAL 21462
CEP 04698-970
SAO PAULO, SP, BRAZIL
PHONE : 0800 - 123123
FAX : [phone]
PAl-YUING CO., LTD.
6 TH FL NO, 148 SUNG KIANG ROAD,
TAIPEI, 10429,TAIWAN R.O.C.
PHONE : [phone]
FAX : [phone]
MRZ STANDARD CO.,LTD.
746 - 754 MAHACHAI RD.,
WANGBURAPAPIROM, PHRANAKORN,
BANGKOK, 10200 THAILAND
PHONE : +66 - 2 - 222 - 9181
FAX : +66 - 2 - 224 - 6795
WO KEE HONG ELECTRONICS SDN. BHD.
NO. 102 JALAN SS 21/35, DAMANSARA
UTAMA, 47400 PETALING JAYA
SELANGOR DARUL EHSAN,
MALAYSIA
PHONE : +60 3 - 7184666
FAX : +60 3 - 7173828
MARANTZ JAPAN, INC.
35- I , 7- CHOME, SAGAMIONO
SAGAMIHARA - SHI, KANAGAWA
JAPAN 228-8505
PHONE : [phone]
FAX : [phone]
FORWARD MARKETING (S) PTE. LTD.
23, LORONG 8, TOA PAYOH,
SINGAPORE 319257.
PHONE : [phone]
FAX : [phone]
SHOCK, FIRE HAZARD SERVICETEST :
CAUTION : After servicing this appliance and prior to returning to customer, measure the resistance between either primary AC
cord connector pins ( with unit NOT connected to AC mains and its Power switch ON ), and the face or Front Panel of product and
controls and chassis bottom.
Any resistance measurement less than 1 Megohms should cause unit to be repaired or corrected before AC power is applied, and
verified before it is return to the user/customer.
Ref.UL Standard N0. 1492(DR700) and No. 813(CDR630).
USA CANADA EUROPE /TRADING
USA CANADA
BRAZIL
(Discagem Direta Gratuita)
TAIWAN
THAILAND
MALAYSIA
In case of difficulties, do not hesitate to contact the Technical
Department at above mentioned address.
JAPAN Technical SINGAPORE
98110MIT
SCAN AUDIO PTY. LTD.
52 CROWN STREET, RICHMOND 3121
VICTORIA
AUSTRALIA
PHONE : +61 - 3 - 9429 - 2199
FAX : +61 - 3 - 9429 - 9309
AUSTRALIA / NEW ZEALAND
KOREA

1. TECHNICAL SPECIFICATIONS
FMTuner
Frequency range............................................................................................................................................ 87.5 ~ 108.0 MHz
F only .................................................................................................................................... 76.0~ 90.0 MHz
Sensitivity ........................................................................................................................................................ 21.2 dBf / 3.2 µV
S/N (Mono/Stereo)..................................................................................................................................................... 75 / 43 dB
F only .......................................................................................................................................... 70 / 50 dB
THD (Mono/Stereo) ...................................................................................................................................................1.5 / 1.5 %
MWTuner
Frequency range............................................................................................................................................... 531 ~ 1602 kHz
U only ................................................................................................................................... 530 ~ 1700 kHz
Sensitivity ................................................................................................................................................................. 500 µV / m
/02, F only ............................................................................................................................................... 400 µV / m
S/N.................................................................................................................................................................................... 50 dB
LWTuner
Frequency range................................................................................................................................................. 153 ~ 279 kHz
Sensitivity ............................................................................................................................................................... 1800 µV / m
Amplifier
Music power................................................................................................................................................... 25 W + 25W (4Ω)
Input sensitivity (AUX) .......................................................................................................................................310 mV / 47 kΩ
U only ............................................................................................................................250 mV / 47 kΩ
S/N (AUX) ......................................................................................................................................................................... 85 dB
CD Player
Channels ................................................................................................................................................................. 2 channels
Frequency response ...............................................................................................................................20 ~ 20,000 Hz ± 3 dB
S/N....................................................................................................................................................................82 dB (1000 Hz)
THD ................................................................................................................................................................0.04 % (1000 Hz)
Output level...................................................................................................................................................................2 V RMS
General
Power supply
/02 version.................................................................................................................................................. AC 230 V, 50 Hz
F version .........................................................................................................................................AC 100 V, 50Hz / 60 Hz
K version ............................................................................................................................. AC 110V / 220V, 50Hz / 60 Hz
KK version.................................................................................................................................................. AC 220 V, 60 Hz
U version .................................................................................................................................................... AC 120 V, 60 Hz
Power consumption ............................................................................................................................................................25 W
Power failure backup time ...............................................................................................................................APPROX. 15 min.
Dimensions ................................................................................................................................ 450(W) x 104(H) x 308(D) mm
Weight............................................................................................................................................................................... 5.8 kg
Table top Speaker LS2021
Speaker
Mid-bass ............................................................................................................................................................................4”
Dome tweeter..................................................................................................................................................................3/4”
Input power
Rated ................................................................................................................................................................... 25 W (6Ω)
Max. ..................................................................................................................................................................... 40 W (6Ω)
Frequency response ...............................................................................................................................80 ~ 20,000 Hz ± 6 dB
Dimensions ................................................................................................................................ 190(W) x 200(H) x 100(D) mm
Weight............................................................................................................................................................................... 1.5 kg
Design and specifications are subject to change without notice.
1-1

2-1. HOWTO DISASSEMBLE MR2020
1.Take the bottom case (001G) apart
(1) Turn MR2020 upside down by the jig (Refer to fig.1-3).
Take care that the top cover will not damaged, especially
the 4 levers.If you don't have the jig, you prepare to put
some magazine or telephone guide under the MR2020
(The height is over 3cm books).
Fig.1 A jig for MR2020
(2) Remove 15 screws as shown in fig.4.
Fig.2 The jig on MR2020 Fig.3 Turning over the MR2020
2-1
Fig.4 Position of 15 screws

(3) While lifting the bottom case, remove the rear panel as
shown in fig.5-6.
Fig.5 Lifting the bottom case
(4) Remove the mains code bush as shown in fig.7.
Fig.6 Removing the rear panel
2-2
Fig.7 Removing the mains code bush

(5) Lift up the bottom case, remove the put the one with turning
to front side (Refer to fig.8).
Remark for reassemble
When you fit the bottom case, remove the lid of the bottom
case (Refer to fig.9) and confirm the arrangement of lead
lines for transformer.(Refer to fig.10).
Fig.9 Removing the lid of the bottom case Fig.10 Arrangement of lead lines
2-3
Fig.8 Taking the bottom case apart

2.Take the top panel (001D) apart
(1) Turn MR2020 upside down by the jig. (Refer to fig.1-3)
Take care that the top cover will not damaged, especially
the 4 levers. If you don't have the jig, you prepare to put
some magazine or telephone guide under the MR2020.
(The height is over 3cm books)
(2) Push the rear panel while keeping hold the top cover (see
fig.11 below).The top cover will move 5mm.(fig.12-13)
Now, 4 screws on the top cover will become accessible.
(fig.14) Take out these screws. (M3 type screw)
Fig.11 Pushing the rear panel
Fig.13 Pushed the rear panel
Fig.12 Before pushing the rear panel
Fig.14 Positions of 4 screws
2-4

(3) Turn the MR2020 to its normal operating position.
(4) Open the top cover of MR2020 by hand.
(5) Take out the 2 screws (M2 type screw) on the top (see
fig.15).
(6) The upper part and lower part of the top cover are
connected to each other with adhesive tape. Separate
these parts by pushing the transparent upper part in the
middle (on CD shaped part) from the lower part, while
holding the lower part.
(7) The upper part and lower part of the top cover were
separated (See fig.16-17).
Fig.16 The upper part of top cover (the reverse side)
Fig.17 The lower part of top cover and the others
2-5
Fig.15 Positions of 2 screws on the top

2-2.REPAIR INTRODUCTION
PREPARATION FOR CD BLOCK
1. Set a disc for repair into product.
2. Turn the product upside down on the jig (Parts
No.*MR2021JIG).Take care that the top cover will not
damaged, especially the 4 levers. (Refer to "How to
disassemble MD2020")
3. For the top panel will not open while repairing, remove
the connecting wires of panel motor from the connector
(J812).
4. Repair and operate it on the upside down position of
the product.
PREPARATION FOR MAIN AMPLIFIER PCB (P704)
1. Main amplifier is BTL output.
2. For removing the main amplifier PCB (P704) from the
product, remove the wire (W802) from the terminal
(WU02) of microprocessor PCB (PU04). Connect
another wire with terminal (WU02) and GND as chassis
instead of the wire (W802).
REMARK
Remove the bottom case from the product, Do not output
signals of over 1W from both channels more than 10
minutes continuously.
2-3.EXPLANATION OF CIRCUITS
FAN OPERATION
The voltage added to the diode (D852) is depended on
the resistance of the thermistor (R857) and resistors
(R855,R858). When the temperature of the heat sink
goes up, the resistance of the thermisor (R857)
decreases, and the voltage added to the diode (D852)
increases.
1. When the temperature of the heat sink is over 70
degrees Celsius, then D852 is on, through R852, Q851
is on, and the fan starts to revolve.
2. When the temperature of the heat sink is approx.100
degrees Celsius or more, through R853, Q853 is on,
and the product is STAND-BY status. But, if the fan
revolve normally, the temperature of the heat sink will
not be over 100 degrees Celsius and not be STAND-
BY status.Therefore, the procedure of the over heat
protection circuit check is as follows;
(1) Connect the test point (J814) with a resistor of 680
ohm.
(2) If the product is STAND-BY status, this circuit is normal.
(3) Remove the resistor of 680 ohm from the test point
(J814).
FAN OPERATION CHECK
Keep outputting 2.5W from both channels of the product.
2-6

When the bottom case is closing. If the fan revolving starts
within 10 minutes, the function is correct working.
Otherwise keep outputting 1W from both channels of the
product when the bottom case is opening.If the fan revolving
starts within 5 minutes, the function is correct working.
REMARK
Do not output over 1W when the bottom case is open.
VCC CONTROL
The regulation of primary voltage is not so higher
intentionally for decreasing the no-load loss.Therefore, this
circuit is used for the product to keep the voltage tolerance
of the power IC.This circuit do not work when the output is
from 0 to approx. 1Vrms.ThenVCC is supplied from D709
only. When the output is more than 1Vrms, through D701-
D704, R722, D706, and Q703 is on, current is supplied
from Q702.When the output is over approx. 3Vrms, D709
is off, and VCC is supplied from Q702 only.
SPEAKER PROTECTION
1. When either terminal of BTL outputs connect with GND
(chassis) by mistake, the speaker protection circuit will
work as follows. through R707-R710, Q704 or Q705 is
on, and Q706 is on.Then #5Pin for Q701 is 0V, power IC
(Q701) will be in power off.Therefore, the product will be
STAND-BY status.
2. When the VCC CONTROL circuit is working correctly,
maximum current of R825 is 1A, and voltage between
R825 load is maximum 0.33V.When both terminals of BTL
outputs are shorted on outputting over 0.25W, R825 is
supplied over 2A, Q807 and Q803 is on, and the product
will be STAND-BY status.
CD 5V ON/OFF CONTROL
The voltage for CD (CD 5V) is supplied from QX04 when
the following conditions are satisfied fully. (for noise and
laser protection)
1. Setting a disc on the product, and QU08 is on.
2. Closing top panel, and #78Pin for QU10 is 0V.
3. The product is in CD mode.
MUTE CONTROL
Mute signals output from microprocessor (QU10) are
"MUTE (Pin No.37)", "MUTE2 (Pin No.7)", and "DSC MUTE
(Pin No.5)".
Fig.1 is workable output terminals by each mute signals,
Fig.2 is the status of each mute.
2-7
Fig.1
Q701(SPK) QN01-QN04
(PHONE) QX05,QX06 (SUB WOOFER) QX07,QX08 (LINE OUT) QE01
MUTE YES YES YES NO NO
MUTE2 NO NO
DSC MUTE NO NO NO NO YES
NO
YESNO