Yamaha ax 492

Page 1

STEREO AMPLIFIER

* X-492

SERVICE MANUAL

YAMAHA mumsaunn SEREOAMPLIFIER Ax-«z cunmecrmp PURE DIRECT
, L, a
i l
2491-»,
me. I v t r A .. I r w s.
, - Q Q Q; Q.
Bass TREBLE BALANCE LOUDNEss see our
PHONES SPEAKERS
A a
(C) E E2!
on a w n
/ IMPORTANT NOTICE
/ This manual has been provided for the use of authorized YAMAHA Retailers and their service personnel.

It has been assumed that basic service pmcedures inherent to the industry, and more specifically YAMAHA

Products, are already known and understood by the users. and have therefore not been restated.

WARNING: Failure to follow appropriate service and safety procedures when servicing this product
may result in personal injury. destruction of expensive components, and failure of the
product to perform as specified, For these reasons, we advise all YAMAHA product
owners that any service required should be performed by an authorized YAMAHA
Retailer or the appointed service representative.

IMPORTANT: The presentation or sale of this manual to any individual of firm does not constitute
authorization, certification or recognition of any applicable technical capabilities,
or establish a principle-agent relationship of any form.

3 The data provided is believed to be accurate and applicable to the unit(s) indicated on the cover. The research,
engineering, and service departments of YAMAHA are continually striving to improve YAMAHA products.

Modifications are, therefore, inevitable and specifications are subject to change without notice or obligation

to retrofit Should any discrepancy appear to exist, please contact the distributor's Service Division,

WARNING: Static discharges can destroy expensive components. Discharge any static electricity
your body may have accumulated by grounding yourself to the ground buss in the unit
(heavy gauge black wires connect to this buss).

IM PORTANT: Turn the unit OFF during disassembly and part replacement Recheck all work before
you apply power to the unit /

TO SERVICE PERSONNEL ADJUSTMENT ....... 6

REMOTE CONTROL PANEL tt-COM DATA ...... 7

REAR PANELS PRINTED CIRCUIT BOARD 8~15

SPECIFICATIONS .......... ...... 3 SCHEMATIC DIAGRAM ........ 16~17

INTERNAL VIEW ...... .. 4 PARTS LIST ..... , ..... ........ 18~25

DISASSEMBLY PROCEDURES ....... 4 REMOTE CONTROL TRANSMITTER 26
/ BLOCK DIAGRAM .. 5

1 ° ° 5 7 YAMAHA CORPORATION

P.O.Box1 .Hamamatsudapan
2.919452 <8) I Printed in Japan '97]

Page 2

AX-492

I TO SERVICE PERSONNEL

1. Critical Components information.

Components having special characteristics are marked&

and must be replaced with parts having specifications equal WALL EQUIPMENT AI'CESI-TgégfgfiE

to those originally installed. . OUTLET UNDER TEST EQUIVALENT
2. Leakage Current Measurement (For 120V Model only). G) 0--

When service has been completed, it is imperative that you |

verify that all exposed conductive surfaces are properly insu- =

lated from supply circuits. 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.
"CAUTION"
9 "F101 : FOR CONTINUED PROTECTION AGAINST RISK OF FIFIE,HEPLACE ONLY WITH SAME TYPE 6.0A,125V FUSE"
4 -V "F103 : FOR CONTINUED PROTECTION AGAINST RISK OF FIRE,REPLACE ONLY WITH SAME TYPE 1.6A,250V FUSE

WARNING: CHEMICAL CONTENT NOTICE!

The solder used in the production of this product contains LEAD. In addition, other electrical/electronic and/or plastic (where
applicable) components may also contain traces of chemicals found by the California Health and Welfare Agency (and possibly
other entities) to cause cancer and/or birth defects or other reproductive harm.

DO NOT PLACE SOLDER, ELECTRICAIJELECTRONIC 0R PLASTIC COMPONENTS IN YOUR MOUTH FOR ANY REASON
WHATSOEVER!

Avoid prolonged, unprotected contact between solder and your skin! When soldering, do not inhale solder fumes or expose eyes
to solder/flux vapor!

If you come in Contact with solder or components located inside the enclosure of this product, wash your hands before handling
food.

I REMOTE CONTROL PANEL

WARNING

Do not change the IMPEDANCE SELECTOR switch
@ setting while the power to this unit is on, otherwise
'3 '5? v this unit may be damaged.

'. , g!

I?

i=2.

IMPEDANCE SELECTOR