7.
TROUBLESHOOTING
No power on
START
Is the display contrast adjustment OK?
Are the power of batteries strong enough?
Does the display appear by pressing
the reset button?
Does the unit sound with each key entry?
Do the batteries make positive contact
with the battery springs?
Y
Is Pin 3 of REG1 5.3 V?
Are the capacitors C8, C9, C10, C11,
C12, and C13 OK?
Replace REG1.
Y
Y
N
N
Y
N
Y
1
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15
N
Adjust the display contrast.
N
Replace the batteries.
Y
Check another function.
Y
Refer to "No/Erratic Display."
N
Adjust the contact and clean the
battery springs.
N
Replace C8, C9, C10, C11, C12, or
C13.
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