Psr-640 Circuit Diagram (Dm, Mks3, Mkh, Mkl, Inv) - Yamaha Portatone PSR-740 Service Manual

A B C

PSR-640 CIRCUIT DIAGRAM (DM, MKS3, MKH, MKL, INV)

1
2
CPU
3
28CC1-8812655
4
DM
to PN1-CN8
5
6
to JACK-JK5
7
8
9
DRAM 4M
10
11
12
PSR-640
A B C
D E F G
MKH
MKS3
MKL
DECODER
RESET
DECODER
SRAM 1M
CPU
DRAM 16M
ROM WAVE1 32M
ROM WAVE2 32M
SWX00B
REGULATOR +3.3V
REGULATOR +5V
DAC
to AM - CN320
D E F G
H I J
D-FF
OR AND
DECODER
AND
PROGRAM1 ROM H 32M
TRANSISTOR ARRAY
DECODER
TRANSISTOR ARRAY
D - FF
PROGRAM2 ROM L32M
SRAM 256K
INVERTER
LCDC
INVERTER
FDC
28CC1-8813199
DC-DC CONVERTER
to AM - CN310
H I J
K L M N
28CC1-8811360
to PN1-CN2
to PN1-CN1
47
L C D
Floppy Disk Drive
INV
2NA-8814265
K L M N
O P Q
PSR-640
1
2
3
28CC1-8811360
4
5
6
7
8
9
to Back - light Assembly
10
Note : See parts list for details of circuit board
11
component parts
: Ceramic Capacitor
: Mylar Capacitor
12
PSR-640
O P Q