Casio SF-4300R Service Manual & Parts List page 19

< No/Erratic display >
Is input 2-Pin of S-81253 (REG1) 6[V]?
Is output 3-Pin of S-81253 (REG1)
5.3[V]?
*Are voltage of several capacitors enough?
Does CPU (LSI1) make positive con-
tact with PCB?
Replace CPU (LSI1)
< High current consumption >
Is there any short circuit?
Are the several capacitors OK?
Resolder/Replace CPU, IC
Y
Y
V1: 1.3 [V]
V2: 2.5 [V]
V3: 2.7 [V]
V4: 3.9 [V]
Y
*CONTRAST: MAX
Y
N
Y
— 17 —
N
Check batteries
N
Replace REG1
N
Check solder part of C6, C7, C8,
C9, C10 or replace.
N
Resolder
Y
Check PCB
N
Replace capacitors