Yamaha MX-2000 User manual

ERE0 POWER AMPLIFIER
CONTENTS
f
IMPORTANT NOTICE
This manual has been provided for the use of authorized Yamaha Retailers and their service personnel.
Ithas been assumed that basic service procedures inhennt to the industry, and more specifically Yamaha
Products, are already knownand understcadby the users, and have thereforenotbeen restated.
WARNING: Failure to follow appropriate service and safety procedures when servicing this product
may result in personal injury, destructionof expensive Eamponentr
and failure of the
product
to perform as specified. Forthese reasons, we advise all Yamaha productownel
rhat all sewib~required should be performed by an authorizedYamaha Retailer or th
appointedservice representative.
IMPORTANT: The presentation or sale of this manual to any individual or firm does not ~onstitute
authorization, certification or remgnitidn of any appllcaMe technical aapabillties, or
establishaprinciple-agentrelationshipofany form.
The data provided is believed to be accurate and applicable to the unit(s) iddftxtted an the wver. The
research, engineering, and service departments of Yamaha are continually striving
to imptwe Yamaha
products. Modifications are, therefore, inevitableand specificationsare subjectt~ chaage wi&out noticeor
obligation to retrofit. Should any discrepancy appear
to exist, please contact the distributor's Servim
Division.
WARNING: Static discharges can destroy expensive components. Dischargeany staticelectricity your
body may have accumulated by groundingyourselfto thegroundbuss in the unit (heavy
gauge blackwires
c~lncct to this buss).
IMPORTANT: Turn the unit OFF during d~sassemblyand parts replacement. Recheck all work before
youapply power
to the unit.
L - -
- -
TO SERVICE PERSONNEL ................. 1 ADJUSTMENTS ........................ 4
FRONTIREAR PANELS ................... 1 PRINTEDCIRCUIT BOARD ............. 5 - 9
SPECIFICATIONS ....................... 2 SCHEMATIC DIAGRAM .................. 10
BLOCK DIAGRAM ...................... 2 WIRING.. ........................... 11
INTERNAL
VIEW.. ..................... 3 PARTSLIST.. .................... 12-20
DISASSEMBLY PROCEDURES
.............. 4
YAMAHA CORPORATION
PO.Box 1. Harnarnatsu. Japan
1.35K-604 liq@ Printed in Japan '88.8

IT0SERVICE PERSONNe'
1. Critical Componentr Information.
Components having special characteristics are marked A
and murt be replaced with parts having specifications equal
to those originally installed. EQUIPMENT AC LEAKAGE TESTER
2. Leakage Current Measurement (Far 12OV Model Only). +UNDER TEST , JlvALENT ,
When service has been completed. it ir imperative that you
verify that all exposed conductive surfaces are properly
insulatedfrom supply circuits.
Meter impedance should be equivalent to 1500ohmshunted WALL
by 0.151iF. OUTLET - -
INSULATINGTABLE -
Leakage current murt not exceed 0.5mA.
Be sure to test for leakagewith the AC plug inbath polarities. POLARIZATION
This amplifier product is equipped with a polarizedalternat-
ing current line plug
(a plug having one bladewider than the
other ).This plugwill fit into the power outlet only one way.
This ia
a safety feature.
I FRONT/REAR PANELS

SPECIFICATIONS
MlnlmumRMSOutput Pow par Chnnrl DIMENSION
20Hz -20kHz
--
0.006% THO, 8S2 13W+130W -
0.005% THD, 651 16(IW+lSMN
18OW+180W
io
0.01% THD, 4n .
Dynamic Pomr per Channel
(by IHFDqnmlcHredrmommesrurinOmethod)
8&2 180W
6n 24w
4n 34ow
zn 49w
~n mw
Pomr Eand Width
OM%THD, 65W. 80 1OHz -100kHr
Dmpinq Factor
_1
-
loo0
-
1kHz, 8n
-
IwutSan$itiuihl/lmpedama
MAININ 130W,8&2 12mV120kn
Fm(uncyR.rpons
20Hz -2OkHz. MAININ +O, -0.3dB
Total HarmonicDMonion IZOHz-ZOkHz)
o :
MAIN IN TO SP OUT, 130~,8n 0.005% -?!
Siil toNoise Ratio (IHF-A-Nwork)
3
MAIN IN(Shorted) 126dB
RriduJNoise (IHF-A-Network) 15@V
ChonlrlSopantion
IkHz, InputShorted, Vol. max.
96d6
Powor SUPMY ACIMV, WHz
Powa Consumption 880W
AC OvNR
Un Sw~tched x 1
WOW max.
'P
Dimwlon (W x H x D) 473
x 170 x 469mm
-
1185/8"x6-11/16
x 187/16"l Unit: mm (inch)
WaIglu 28kg I61lbs 11 or)
*~mot~on: m ubbt m dmm without notice.
IUI .- U.S.A. Modal
ICI ... DWm hl&
BLOCK DIAGRAM
P101,103.ID5.107
INPUT
SP otr
ANm
PW LEVa METER
PrnTECTlON *=
MLTH ALP
0%-Zm UNSWITCHEO
D301.302

.INTERNAL VIEW
TOP VlEW
BOTTOM VlEW
0 ELECTRICALCAPACITOR:
22000pF80V x 2
OINPUTCIRCUITBOARD:
VOLTAGE AMP SECTION 81 DIRECT
ERROR CORRECTIONSECTION
@MAINCIRCUITBOARD (Lch):
H.C.A. POWER STAGE
@POWER TRANSFORMER
U model
: XE669001
Cmodel : XE670001
@MAIN CIRCUITBOARD (Rch):
H.C.A. POWER STAGE
@POWERSUPPLY CIRCUIT BOARD (2):
OUTPUTCOIL 81 OUTPUT ERROR
POWERSUPPLY CIRCUIT BOARD (11:
POWER SUPPLY SECTION
(* B1.f BZandiB3)
&PROTECTION CIRCUITSECTION
@METER CIRCUIT BOARD (1)

DISASSEMBLY PROCEDURES
(Removeparts indisassembly order as numbered.)
1. Removal ofTop Cover Ass'y
- Remove 11screws ( @ ) in Fig. 1.
2. Removalof BottomCover
Remove 24 screws
( @ ) in Fig. 1.
3. Removalof Wood Panel Ass'y
Remove 8 screws ( @ ) in Fig. 1.
4. Removalof Front Panel
Remove 4 screws ( @ ) and plastic rivet ( @ ) in
Fig. 1.
--
8
Q
Fig. 1
- ADJUSTMENTS
IdlingAdjustment
1) Removethe wood panel assembly.
2) Adjust VR201 (both
L and R) so that the voltage
between test pins TP1 and TP2 in the main circuit
boardbecomes DCGOmV
+ 590mV.
MainCircuit Board
I
VR201 TPl TP2
,
=
MeterAdj~
Connect a
. ,. . . ,.
ustment
8.9 dumm
-.-- ,.
1) y load.
2) Aalusr vnrud IL ch) and VR404 (R ch) so that
meter indicator reads OW with no signal applied.
3) Apply 1kHz sine wave signal to INPUT and set the
signal level so that 28.3Vrms voltage
is obtained at
both ends of the dummy load.
4) Adjust VR401 (L ch) and VR402 (R ch) so that the
meter indicator reads 1OOW.
5) eter indicator reads OW with no
iust again if necessary.
Recheck t
signal appl
hat the m
ied and adj
lvlerer Circuit Board
1

.PRINTED CIRCUIT BOARD(Pattern side)
Note) ZTEi : Component ride
I Main Circuit Board 1
(L channel is the same as R channel)

FROM :POWER SUPPLY I I)
TO : POWER SUPPLY ( I)
TO : POWER SUPPLY ( I)
a
TO:POWER SUPPLY (2

%WER SUPPLY (1 1
.:
FROM : POWER SUPPLY (1 1
METER Lch
J
ER SUPPLY (31
PROTECTION POWER SPEAKERS OFF
-
C
FR0M:PQWER SUPPLY (1)-
L Meter Circuit Board (2)

L
1
-
2
-
5
-
4
A
5
A
6
A
IW-1000
l PRINTED CIRCUIT BOARD(Pattern side)
Notal ZTES : Component side
FROM : POWER SU
Meter CircuitBoard
I Power Supply Circuit Board (3) 1
FROM : METER ( I )
Opention Check of InputCircuit Bbafd Alone
Connect IN and
E of board-in going to R channel
main circuit board of the input circuit board and IN
and
E of board-in goingto L channel one to sockets
R, RE, LE and L which receive board-inof the power
circuit board
(2) withwires.
Connect iaOV power source to +82, E and -82 of
board-in goingto the power supply circuit board
L1 I
I Input Circuit Board
and then wnnect EM terminal to -82 with 47k.Q.
1
,,..
-.
resistance included. !
TO : MAIN R 13%
-
C
0
K
6 9
6 C
D

m-20a0
WIRING
150mA 8Vx 6
METER (I I
POWER SUPPLY (1)
POWER SUPPLY (2)

-2000
LIST
I ELECTRICAL PARTS
=WARNING
Componentshaving special characteristicsare marked and must be replaced
with Parts having specificationsequal to those originally installed.
*Carbon resistors Il/BW or 1/4W) are not included in the ELECT
PARTS list. For the parts No. of the carbon resistor, refer to p. 20.
E
E
XNew Parts (%%%a) NR

*New Parts (%I&$&) NR

%New Parts (M%BI$) NR

i
I
L
*
i
L
iNsw Parts (RfLlbb) NR

IMECHANI SM PARTS NO-, 9 : Diameter

I EXPLODED VIEW
Tighten this scraw.securely as it grounds the circuit
the chartis. \

I Part No. 1
k,..
41 1 Fi 38 j 41 jOO(Ceramic Cap. 0.0lpF t52i
42 / CB i 60 i 08 i 10 1 Cover
%!New Parts (%R%&) NR

Parts List for Carbon Resistor