Circuit Description - Casio WK-1800 Service Manual

KEY MATRIX
KC0
FI0
SI0
FI1 B11
SI1 B12
FI2 G21 G#21
SI2 G22 G#22
FI3 D#31
SI3 D#32
FI4 B31
SI4 B32
FI5 G41 G#41
SI5 G42 G#42
FI6 D#51
SI6 D#52
FI7 B51
SI7 B52
FI8 G61 G#61
SI8 G62 G#62
FI9 D#71
SI9 D#72
Note: Each key has two contacts, the first conatct 1 and second contact 2.
NOMENCLATURE OF KEYS
E1 C2

CIRCUIT DESCRIPTION

KC1 KC2
E11 F11 F#11
E12 F12 F#12
C21 C#21 D21
C22 C#22 D22
A21 A#21
A22 A#22
E31 F31 F#31
E32 F32 F#32
C41 C#41 D41
C42 C#42 D42
A41 A#41
A42 A#42
E51 F51 F#51
E52 F52 F#52
C61 C#61 D61
C62 C#62 D62
A61 A#61
A62 A#62
E71 F71 F#71
E72 F72 F#72
Key
Second contact 2
C3 C4
KC3 KC4 KC5
G11 G#11
G12 G#12
D#21 E21
D#22 E22
B21 C31
B22 C32
G31 G#31
G32 G#32
D#41 E41
D#42 E42
B41 C51
B42 C52
G51 G#51
G52 G#52
D#61 E61
D#62 E62
B61 C71
B62 C72
G71
G72
First contact 1
C5
— 6 —
KC6 KC7
A11 A#11
A12 A#12
F21 F#21
F22 F#22
C#31 D31
C#32 D32
A31 A#31
A32 A#32
F41 F#41
F42 F#42
C#51 D51
C#52 D52
A51 A#51
A52 A#52
F61 F#61
F62 F#62
C#71 D71
C#72 D72
FI
KC
SI
C6 C7 G7