Yamaha PORTATONE KB-280 Service Manual page 12

KB-280
13. Disassembling Keyboard Assembly
(Time required: About 12 minutes)
13-1 Remove the lower case assembly. (See procedure 1.)
13-2 White Keys and Black Keys:
13-2-1 White and black keys for one octave unit are integrated
as a set. There are five sets in total. Only the C6 white
key, unlike the other keys, is not integrated in a set.
(Fig. 12)
To remove a set, remove the four (4) each screws
marked [200B]. The white and black keys in the set
can then be removed. (Fig. 12)
When removing, unfasten the two (2) hooks at the
back of the black keys upward, and lift the white
and black keys while pulling them toward you a little.
(Photo 1)
13-2-2 To remove the white key C6, remove the screw
marked [200C], unhook as described in Procedure
13-2-1, and pull out toward you. (Fig. 12)
Hook
<Top view (Lower Case Assembly)>
[180A]
[190A]
12
(Photo 1)
Rubber contact
[180A]
61L
[180]: Bind Head Tapping Screw-B 3.0X8 MFZN2W3 (WE774300)
[190]: Bind Head Tapping Screw-P SP 3.0X12 MFZN2B3 (WF491900)
13-3 Rubber Contacts
13-3-1 Remove the white and black keys corresponding
to the rubber contacts to be removed.
(See Fig. 12 and Procedure 13-2.)
13-3-2 Remove the rubber contacts. (Photo 2, Fig. 13)
13-4
Circuit Board 61L
13-4-1 Remove the white and black keys from C1 to B3.
(See Fig. 12 and Procedure 13-2.)
13-4-2 Remove the four (4) screws marked [180A] and
eight (8) screws marked [190A]. The circuit board
61L can then be removed. (Fig. 13)
* When installing the circuit board 61L, tighten
the screws 1 through 12 in numerical order as
shown in the figure for circuit board "61L" in
Fig. 14. (Fig. 14)
13-5 Circuit Board 61H
13-5-1 Remove the white and black keys from C4 to C6.
(See Fig. 12 and Procedure 13-2.)
13-5-2 Remove the three (3) screws marked [180B] and
five (5) screws marked [190B]. The circuit board
61H can then be removed. (Fig. 13)
Rubber contact
[180A]
[180B]
[190A] [190B]
(Fig.13)
Rubber Contact
(Photo 2)
Rubber contact
[180B]
[190B]
61H