Casio SF-4400 - Page 18

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N
Replace PCB
< No key input >
1
N
Replace CPU (LSI1)
Y
Y
Is 13-Pin of CPU (LSI1) sending
the signal?
Y
N
Replace DET1
N
Replace CPU (LSI1)
Does RAM make positive contact with
PCB?
Y
N
Resolder RAM (LSI2 or LSI3)
Does key make positive contact with PCB
Ass’y
Y
Does CPU make positive contact with PCB?
N
Replace CPU (LSI1)
Y
Resolder CPU (LSI1)
Is 11-Pin of CPU (LSI 1) sending the
signal?
Replace RAM (LSI2 or LSI3) or CPU (LSI1)
Is 1-Pin of S-80752AN (DET 1) 5[V]?