Yamaha PORTATONE KB-280 Service Manual page 9

3. AM Circuit Board
(Time required: About 4 minutes)
3-1 Remove the "MASTER VOLUME" knob as shown
in Fig. 4. (Fig. 4)
3-2 Remove the lower case assembly. (See procedure 1.)
3-3 Remove the TW2 connector assembly soldered to
the TWL circuit board. (Fig. 5)
3-4 Remove the seven (7) screws marked [210A], three
(3) screws marked [210B], two (2) screws marked
[210C] and the screw marked [210D]. The AM circuit
board can then be removed. (Fig. 5)
3-5 Pull out the push knob from the AM circuit board.
(Fig. 6)
4. LCD Unit
(Time required: About 3 minutes)
4-1 Remove the lower case assembly. (See procedure 1.)
4-2 Remove the two (2) screws marked [210E] and four
(4) screws marked [210F]. The LCD unit can then
be removed. (Fig. 5)
<Bottom view>
[A]
Speaker
cable
[210M]
Speaker R (Tweeter)
<Rear view>
TWR (PN 5/6, 6/6)
[210G]
MIDI
(AMJK 2/6)
TW3 Connector assembly
[210]: Bind Head Tapping Screw-B 3.0X8 MFZN2W3 (WE774300)
LCD Unit
[210E] [210E] [210A] [210C]
[210F] [210A] AM [210A]
(AMJK 1/6)
TW2 Connector assembly
(Fig. 5)
Knob
(Fig.4)
Push knob
AM
(Fig.6)
[210D]
AM
(AMJK 5/6)
AM
(AMJK 4/6) TWL
[210L]
[210B]
Speaker L (Tweeter)
KB-280
(PN 5/6, 6/6)
[A]
Speaker
cable
9