Sharp ZQ-6100M Operation Manual page 176

Reset
When trouble occurs
An impact or a strong external electric field may clear the display or fill
it with meaningless symbols, leaving the Organizer inoperative. If so,
press the RESET switch on the back of the Organizer with the tip of a
ball-point pen or similar non-breakable object.
e The impact or extemal electric field may erase some or all of the
Organizer's memory.
All reset operation
described above, perform the following:
ALL DATA
CLEAR
OK rH 7
2. Press [N].
Caution: Do not press in step 2. This will delete all data.
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