Casio CTK-4200 - Circuit Description

CTK-4200
– 5 –
CIRCUIT DESCRIPTION

KEY MATRIX
KC0 KC1 KC2 KC3 KC4 KC5 KC6 KC7
FI0 C2
1
C2#
1
D2
1
D2#
1
E2
1
F2
1
F2#
1
G2
1
SI0 C2
2
C2#
2
D2
2
D2#
2
E2
2
F2
2
F2#
2
G2
2
FI1 G2#
1
A2
1
A2#
1
B2
1
C3
1
C3#
1
D3
1
D3#
1
SI1 G2#
2
A2
2
A2#
2
B2
2
C3
2
C3#
2
D3
2
D3#
2
FI2 E3
1
F3
1
F3#
1
G3
1
G3#
1
A3
1
A3#
1
B3
1
SI2 E3
2
F3
2
F3#
2
G3
2
G3#
2
A3
2
A3#
2
B3
2
FI3 C4
1
C4#
1
D4
1
D4#
1
E4
1
F4
1
F4#
1
G4
1
SI3 C4
2
C4#
2
D4
2
D4#
2
E4
2
F4
2
F4#
2
G4
2
FI4 G4#
1
A4
1
A4#
1
B4
1
C5
1
C5#
1
D5
1
D5#
1
SI4 G4#
2
A4
2
A4#
2
B4
2
C5
2
C5#
2
D5
2
D5#
2
FI5 E5
1
F5
1
F5#
1
G5
1
G5#
1
A5
1
A5#
1
B5
1
SI5 E5
2
F5
2
F5#
2
G5
2
G5#
2
A5
2
A5#
2
B5
2
FI6 C6
1
C6#
1
D6
1
D6#
1
E6
1
F6
1
F6#
1
G6
1
SI6 C6
2
C6#
2
D6
2
D6#
2
E6
2
F6
2
F6#
2
G6
2
FI7 G6#
1
A6
1
A6#
1
B6
1
C7
1
SI7 G6#
2
A6
2
A6#
2
B6
2
C7
2
Each key has two contacts, the rst contact
1
and second contact
2
.
NOTE: The diagram below illustrates how the contacts work.
Key
Second contact
 First contact 
FI
KC
SI

NOMENCLATURE OF KEYS
C2 C3 C4 C5 C6 C7