Casio SF-5300B

— 17 —
No/Erratic display
N
Y
Is input Pin 2 of REG1 6 V?
N
Adjust the contact and clean
the battery springs.
Y
Is output Pin 3 of REG1 5.3 V?
N
Y
N
Y
Are the voltages of V1, V2, V3, and V4
strong enough?
V1: 1.3 V
V2: 2.5 V
V3: 2.7 V
V4: 3.9 V
Is the soldering of LSI1 poor?
N
Replace LSI1.
Y
Resolder.
High current consumption
START
Y
N
Are the capacitors C8, C9, C11, C12,
and C13 OK?
N
Y
Is there any short circuit on the PCB
assembly ?
START
Note:
Contrast: Maximum
Replace C1, C2, C3, or C4.
Repair shorts.
Resolder or replace LSIs and ICs.
Replace the capacitor(s).
Replace REG1.
Replace the batteries.
Are the power of batteries strong enough?