Yamaha ax 900

Page 1

STEREO INTEGRATED AMPLIFIER

AX-900/AX-900U

SERVICE MANUAL

I CONTENTS

' TO SERVICE PERSONNEL
FRONT PANELS . . . . . . .

REAR PANELS . .
SPECIFICATIONS . .
INTERNAL VIEW . .
BLOCK DIAGRAM .

IMPORT} T NOTICE

This manual has been provided for \he use of aurhorlled Yamaha Retailers and rhcir sarvvce ptrsonnel,
It has been assumed that basic service procedures inherant to rhe indusrry. and mar: Xpeclflciiiv Yamaha
Products, are already known and undersload by (he uwrs. and have therefore no! been restated.

WARNING: Faiiure (a follow apprapriare service and safety procedures when servicing [his producr
may resulr in personal injury, dusrruczion of expensive componems and failure or the
product I!) perform as soccliicdr For xhese reasons, we advise ail Vamahz product owners
mar all strwce required should be performed by an aurhorlzcd Yamaha Retailer or the
appointed service representativer

IMPORTANT: The presentation or sale of this manual to any individual or firm does no! consumre
authorization. certification or rcoognltron of any applicable technical capabilitm, or
establish a principle-age"! relationship of any form,

The data provided is believed to be accurate and applicable to the unlrisi indicated on the cave! The

research, engineering, and service deparrmenrs of Vamaha are continually striving to improve Yamaha

producrs. Modifications are, rhereforc, inevitable and specifications are subiecr to change without have: or

obligation to rerrufilu Should any discrepancy appear r0 exisr please conucr me distributor's 5w.

Division.

WARNING: Siam discharges can desrroy expensive components. Discharge any sraxiceieclricityyaur
body my have accumulated by grounding yourself :0 m ground buss in me unlr (heavy
gauge black wrres connect w this buss)

IMPORTANT: Turn the Link OFF during disassembly and parts replacemcnt. Recheck All work before
you apply power 10 rhe unit.

DISASSEMBLY PROCEDURES r
ADJUSTMENTS . . . . . . .
PRINTED CIRCUIT BOARD
WIRING..............
SCHEMATICDIAGRAM.................
PARTSLIST.......................13

..5
..5
~10

....... 11

. 12
~21

a YAMAHA

NIPPON GAKKI CO. LTD. HAMAMATSU, JAPAN

3.3k-38l @Printed in Japan.

BBVIZ

nooo-xv

Page 2

AX-900/AX-9OOU

I TO SERVICE PERSONNEL

1. Critical Components Information.
Components having special characteristics are marked
A and must be replaced with parts having specifica-
tions equal to those originally installed.

EQUIPMENT AC LEAKAGE TESTER
2. Leakage Current Measurement (For 120 V Model UNDER 1-551- OR EQUIVALENT
Only). '
When service has been completed, it is imperative that :D_ _
you verify that all exposed conductive surfaces are ®
properly insulated from supply circuits. WALL I
OUTLET INSULATING TABLE :

0 Meter impedance should be equivalent to 1500 ohm
shunted by 0.15uF.

O Leakage current must not exceed 0.5mA.

0 Be sure to test for leakage with the AC plug in both
polarities.

I FRONT PANELS

0 AX-900
YAMAHA mm. mm mm: mm mm
s mm
m, 9.3m Far-x
A . a -st. WWW. - m -m
Elli] '2: - :29. l l l
m Wm M m
BvfiA§ FLTEF FIJER Na
:21 a
Y5 we grew-
as... «- mum. Mm' "an
O as m,
0 AX-QQOU

YAMAHA mm. mm mam was Axmu

Imbsxzv .wnm
nuns '
a A -uAY -vmez-mss. uvmwn-rupan - an -m

l:&flr_

1N suasm: W Mons mow
nleAas Elven nus:
an» m n w - mun g...
E = = :
Au- «1 - w - m - m
WEE-.5 BALANCE LOWE w. s urns: nun.
um! um ...,.. Mm 13$:sz '3 "W1 . mm

OOQQQ -"_
l==mr J