Yamaha MU128, Service Manual

MU128

19

NG

02  BATTERY
                                err

3.

LCD DOT BLINK AND CONTRAST

Visually check to see if all of the white dots of the LCD
are highlighted black.
Also check to see if the back light is lit properly. Then
press the [SELECT] button and make sure that the
contrast is changed in eight stages.

Ending the test
Press the [ENTER] button. You will then go to the next
test.

4.

LED

04  LED

Make sure that th

e LEDs are lit in order of [MU],

[PLG-1],

 [PLG-2], [PLG-3], [PLAY], 

[UTIL],

 [MODE],

[EDIT], [EFFECT], and [EQ]. Also make sure that
all of the LEDs are then lit and extinguished.

Ending the test
Press the [ENTER] button. You will then go to the
next test.

5.

SWITCHES

05  SWITCH
[Piano]

[TURN ON/OFF] the panel switches from [Piano] to

[Value

in] accordance with the 

switch

 name displayed

on the LCD.

When the above step is done, a specific sound is

heard if the switch being tested is in its normal condition.

You will then go to the test of the next switch.
If the switch being tested fails in the test, you will not
go to the test of the next 

switch

 even though you

press the switch directed on the LCD.

Displaying the test result
OK

05  SWITCH
                                      ok

NG

None

Ending the test
When the test of the switches from [Piano] to [Value          ]
has been finished, you will go to the next test. If you
think that the switch being tested has fails in the test,
turn OFF the equipment once and restart the test.

6.

DIAL

06  DIAL
Right 0-10=00

Make that the dial is working properly. Slowly turn the
dial clockwise until a value of 10 is obtained for "00"
on the LCD. When the value 10 is obtained, the next
item illustrated below will appear.

06  DIAL
Left  0-10=00

Slowly turn the dial counterclockwise until a value of
10 is obtained for "00" on the LCD.

Displaying the test result
OK

06  DIAL
                              ok

NG

06  DIAL
                              err

7.

MIDI 1 A Front

Use a MIDI cable and connect the MIDI IN A (front)
connector to the MIDI OUT connector. Then conduct
the test.
Before starting the test, select MIDI under HOST
SELECT.

07  MIDI 1A Front

The test pattern (AA 50 5F) will be sent from MIDI
OUT and received by MIDI IN (front). The result of the
test pattern received will then be judged.

Displaying the test result
OK

07  MIDI 1A Front
                              ok

NG

07  MIDI 1A Front
                              err

8. MIDI 

2 

A 

Rear

Use a MIDI cable and connect the MIDI IN A (rear)
connector to the MIDI OUT connector. Then conduct
the test.
Before starting the test, select MIDI under HOST
SELECT.

08  MIDI 2A Rear

The test pattern (AA 50 5F) will be sent from MIDI
OUT and received by MIDI IN A (rear). The result
of the test pattern received will then be judged.

Displaying the test result
OK

08  MIDI 2A Rear
                              ok

NG

08  MIDI 2A Rear
                              err