Yamaha mx12 4

Page 1

MIXING CONSOLE

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SERVICE MANUAL

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I CONTENTS (E a)

SPECIFICATIONS (fiéflfi) .................................................. 2/4
PANEL LAYOUT (/WUb w 77 I~) .......................... 6
CIRCUIT BOARD LAYOUT (1:. y I~ I/ 4 7 r7 I~). .8
DIMENSIONS (THEE) ............................... .9

BLOCK DIAGRAM (7n 7 7 54 777 A)

DISASSEMBLY PROCEDURE (fifififi) .. ....12
LSI PIN DESCRIPTION (LSIfi-Tflfiéi) ....15
IC BLOCK DIAGRAM (IC 7 E! -y 7|) ..... 16
CIRCUIT BOARDS (9 - Igflim) ...... 17
INSPECTIONS (fig) .................. 26/31
WIRING (Emma ........ 36
CIRCUIT DIAGRAM (Efigl) ............................................ aa~53
PARTS LIST

PA YAMAHIQAIEQEE

1996122069800 23mm M Printedin Japan9611

Page 2

MX12/4

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 procedures inherent to the industry, and more specifically Yamaha Products. are already known and under-
stood 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 per-
sonal injury, destruction of expensive components and failure of the product to perform as specified. For
these reasons, we advise all Yamaha product owners that all service required should be performed by an
authorized Yamaha Retailer or the appointed service representative,

IMPORTANT: This presentation or sale of this manual to any individual or firm does not constitute authorization, certifi-
cation, recognition of any applicable technical capabilities, or establish a principal-agent relationship of
any forrnt

The data provided is belived to be accurate and applicable to the unitls) indicated on the cover. The research engineering, and
service departments of Yamaha are continually striving to improve Yamaha products. Modifications are, therefore, inevitable
and changes in specification are subject to change without notice or obligation to retrofit. Should any discrepancy appear to
exist, please contact the distributors Service Division.

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

IMPORTANT: Turn the unit O_FF during disassembly and parts replacement Racheck a_ll work before you apply power
to the unit.

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 SOLDEH. ELECTRICAL/ELECTRONIC 0R PLASTIC COMPONENTS IN YOUR MOUTH FOR ANY REASON WHAT
SO EVER!

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 orcomponents located inside the enclosure of this product, wash your hands before handling
food.

I WARNING

Components having special characteristics are marked A and must be replaced with parts having specification equal
to those originally installed

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