Verifying Proper Operation (Self-Tests) - HP 12C Platinum Owner's Handbook Manual

196 Appendix F: Battery, Warranty, and Service Information
To install a new battery, use the following procedure:
1. With the calculator turned off, slide the battery cover off.
2. Remove the old battery.
3. Insert a new battery, with positive polarity facing outward.
4. Replace the battery cover.
Note: Be careful not to press any keys while the battery is out of the calculator. If
you do so, the contents of Continuous Memory may be lost and keyboard control
may be lost (that is, the calculator may not respond to keystrokes).
5. Replace the battery compartment cover and press ; to turn on the
power. If for any reason Continuous Memory has been reset (that is, if its
contents have been lost), the display will show Pr Error. Pressing any key
will clear this message.

Verifying Proper Operation (Self-Tests)

If it appears that the calculator will not turn on or otherwise is not operating
properly, use one of the following procedures.