Disassembly Procedure; Lower Case Assembly; Dm Circuit Board; Inv Circuit Board - Yamaha Portatone PSR-740 Service Manual

PSR-740/PSR-640

DISASSEMBLY PROCEDURE

1.

Lower Case Assembly

1-1 Remove the sixteen (16) screws marked [260] and the
two (2) screws marked [270A]. The lower case
assembly can then be removed. (Fig.1)
[ 260 ]
2.

DM Circuit Board

2-1 Remove the lower case assembly. (See procedure 1.)
2-2 Remove the four (4) screws marked [240A] and the
screws (PSR-740: 20pcs, PSR-640: 11pcs) marked
[250A]. The shield cover L can then be removed.
(Fig.2)
2-3 Remove the one (1) screw marked [250B]. The DM
circuit board can then be removed. (Fig.3)
3.

INV Circuit Board

3-1 Remove the lower case assembly. (See procedure 1.)
3-2 Remove the four (4) screws marked [250C]. The INV
circuit board can then be removed. (Fig.2)
4. MIC Circuit Board (PSR-740 only)
4-1 Remove the lower case assembly. (See procedure 1.)
4-2 Remove the five (5) screws marked [240B]. The MIC
circuit board can then be removed. (Fig.2)
5. MIC-JACK Circuit Board (PSR-740 only)
5-1 Remove the lower case assembly. (See procedure 1.)
5-2 Remove the three (3) screws marked [240C]. The
MIC-JACK circuit board can then be removed. (Fig.2)
6. AM(AM), AM(PSW) and AM(VR) Circuit Boards
6-1 Remove the lower case assembly. (See procedure 1.)
6-2 AM(AM) Circuit Board:
Remove the seven (7) screws marked [240D]. The
AM(AM) circuit board can then be removed. (Fig.3)
6-3 AM(PSW) Circuit Board:
Remove the two (2) screws marked [240E]. The
AM(PSW) circuit board can then be removed. (Fig.3)
6-4 AM(VR) Circuit Board:
Remove the three (3) screws marked [240F]. The
AM(VR) circuit board can then be removed. (Fig.3)
10
[ 260 ]
[ 260 ]
[260]:
[270A]: Bind Head Tapping Screw-P 3.0 X 25 MFZN2Y (VK228100)
Fig.1
[ 270A ]
Bind Head Tapping Screw-P 3.0 X 12 MFZN2Y (EP600300)
[ 260 ]
[ 260 ]