Circuit Description - Casio LK-90TV Service Manual

KEY MATRIX
KC0
FI0 C21
SI0 C22
FI1 G2#1
SI1 G2#2
FI2 E31
SI2 E32
FI3 C41
SI3 C42
FI4 G4#1
SI4 G4#2
FI5 E51
SI5 E52
FI6 C61
SI6 C62
FI7 G6#1
Note: Each key has two contacts, the first contact 1 and second contact 2.
NOMENCLATURE OF KEYS
C2 C3

CIRCUIT DESCRIPTION

KC1 KC2
C2#1 D21
C2#2 D22
A21 A2#1
A22 A2#2
F31 F3#1
F32 F3#2
C4#1 D41
C4#2 D42
A41 A4#1
A42 A4#2
F51 F5#1
F52 F5#2
C6#1 D61
C6#2 D62
A61 A6#1
Key
Second contact
2
C4
KC3 KC4
D2#1 E21
D2#2 E22
B21 C31
B22 C32
G31 G3#1
G32 G3#2
D4#1 E41
D4#2 E42
B41 C51
B42 C52
G51 G5#1
G52 G5#2
D6#1 E61
D6#2 E62
B61 C71
1
First contact
C5
— 4 —
KC5 KC6
F21 F2#1
F22 F2#2
C3#1 D31
C3#2 D32
A31 A3#1
A32 A3#2
F41 F4#1
F42 F4#2
C5#1 D51
C5#2 D52
A51 A5#1
A52 A5#2
F61 F6#1
F62 F6#2
FI
KC
SI
C6
KC7
G21
G22
D3#1
D3#2
B31
B32
G41
G42
D5#1
D5#2
B51
B52
G61
G62
C7