Yamaha MU128, Service Manual

MU128

MU128

MU128

MU128

MU128

88888

1.

Bottom Assembly

1-1

Remove the four (4) screws marked [60], the two
(2) screws marked [70] and the two (2) screws
marked [80]. The bottom assembly can then be
removed. (Fig. 1)

[60]:

Bind Head Tapping Screw-B 3.0X8  MFNI33 (VF646900)

[70]:

Bind Head Tapping Screw-B 3.0X6  MFZN2BL (EP600230)

[80]:

Flat Head Tapping Screw-C 3.0X8  MFNI33 (V2500600)

(Fig. 1)

2.

Top Assembly

2-1

Remove the bottom assembly. 

(See Procedure 1.)

2-2

Remove the A/D INPUT knob.

2-3

Remove the two (2) screws marked [30]. The
Top Assembly can then be removed. (Fig. 2)

*

When assembling the bottom assembly,
tighten the screws in the order shown in the
figure below.

(Fig. 2)

3.

DM Circuit Board and ADVR1 Circuit Board

3-1

Remove the bottom assembly. (See Procedure 1.)

3-2

Remove the Top assembly. (See Procedure 2.)

3-3

Remove the four(4) screws marked [T40a]. The DM
circuit board can then be removed. (Fig. 3)

3-4

Remove the two(2) screws marked [T40b]. The
ADVR1 circuit board can then be removed. (Fig. 3)

[30]:

Flat Head Tapping Screw-C 3.0X8  MFNI33 (V2500600)

[T40]:

Bind Head Tapping Screw-B 3.0X6  MFZN2BL (EP600230)

(Fig. 3)

(Bottom Veiw)

(Top View)

(Front)

(Rear)

(Rear View)

(Bottom)

(Top)

(Bottom View)

(Front)

(Front)

(Rear)

(Rear)

5.

PSW Connector Assembly, PMD Circuit Board and ADMVR2 Circuit Board

4.

LEDSW1 Circuit Board and LEDSW2 Circuit Board and LCD and RE Circuit Board

(Fig. 5)

(Fig. 4)

4-1

Remove the bottom assembly. (See Procedure 1.)

4-2

Remove the two (2) screws marked [30]. The front
assembly can then be removed. (Fig. 2)

4-3

Remove the five (5) screws marked [100]. The
LEDSW1 circuit board can then be removed. (Fig. 4)

4-4

Remove the four (4) screws marked [80A]. The

LEDSW2

 circuit board can then be removed. (Fig. 4)

4-5

Remove the four (4) screws marked [80B]. The LED
can then be removed. (Fig. 4)

4-6

Remove the two (2) screws marked [120] and the
encoder knob. The RE circuit board can then be

[40]:

Bind Head Tapping Screw-B 3.0X6  MFZN2BL (EP600230)

[50]:

Bind Head Tapping Screw-B 2.6X10  MFZN2Y (VD791000)

[80]:

Bind Head Tapping Screw-B 2.6X10  MFZN2Y (VD791000)

[20d]:

Bind Head Tapping Screw-B 2.6X6  MFZN2Y (VC069600)

(INSIDE  VIEW)

*

Connection of the cable bundles to the CN9
of the DM circuit board is shown in Fig 6-1.

(Fig. 6-1)

[100]:

Bind Head Tapping Screw-B 2.6X6  MFZN2Y (VC069600)

[120]:

Bind Head Tapping Screw-B 3.0X6  MFZN2BL (EP600230)

(Fig. 6-2)

Front Assembly

*

Be careful not to injure your

fingers for the sharp edge

of the rear shield.

5-1

Remove the bottom assembly. (See Procedure 1.)

5-2

Remove the front assembly. (See Procedure 4-2.)

5-3

Remove the volume knob.

5-4

Remove the two (2) screws marked [40] and the
screw marked [50]. The PSW connector assem-
bly and the JACK assembly can then be removed.

(Fig. 4)

5-5

Remove the two (2) screws marked [20d]. The PMD
circuit board, the ADMVR2 circuit board and the front
shield can then be removed. (Fig. 5)

5-6

Remove the  front shield marked [50] from the PMD
circuit board. (Fig. 5)

3-5

Melt the solder on the four(4) points marked [A] in
figure 6-2 and remove the rear shield. (Fig. 3)

removed. (Fig. 4)