Yamaha F-20B, Service Manual

Page: 5 / 16

5
F-20B
DISASSEMBLY PROCEDURE
[30] x 4
[60a]
[A]
BackBoard
Speaker Pre-Main Unit Pre-Main Unit
(Fig.1)
MAIN1/2 Circuit Board
Needle-nose plier Needle-nose plier
MAIN1/2 Circuit Board
[P40] [P40]
(Fig. 2)
[30]: Truss Head Screw 4.0X25 MFZN2BL (VN347600)
[A]: Bind Head Tapping Screw 4.0X25 FCRM3-BL (EI340256)
[60a]: Bind Head Screw (VB403600)
1. Pre-Main Unit (Time required: about 2 min)
1-1 Remove the eight (8) screws marked [A]. The back
board can then be removed. (Fig.1)
1-2 Pull out the speaker wires. (Fig.1)
1-3 Remove the four (4) screws marked [30]. The pre-
main unit can then be removed by sliding it
backward. (Fig.1)
2. Speaker (Time required: about 2 min)
2-1 Remove the back board. (See Procedure 1-1)
2-2 Pull out the speaker wires. (Fig.1)
2-3 Remove the four (4) screws marked [60a]. The
speaker can then be removed. (Fig.1)
3. MAIN 1/2 Circuit Board
(Time required: about 4 min)
3-1 Remove the pre-main unit. (See Procedure 1)
3-2 Remove the five (5) knobs marked [P100] and the
five (5) hexagonal nuts marked [C]. (Fig.5)
3-3 Remove the hexagonal nut marked [A120] and the
hexagonal nut marked [A140]. (Fig.5)
3-4 Push the hooks of the spacer support (at the arrow
symbol area of illustration) with a needle-nose plier
to unlock.
The MAIN 1/2 circuit board can then be removed.
(Fig.2)