HP -225 Owner's Manual page 155

Environmental Limits
In order to maintain product reliability, you should observe the fol-
lowing temperature and humidity limits of the HP-22S:
B Operating temperature: 0° to 45°C (32° to 113°F).
B Storage temperature: —20° to 65°C (—4° to 149°F).
B Operating and storage humidity: 90% relative humidity at 40°C
(104°F) maximum.
Determining If the Calculator Requires
Service
Use these guidelines to determine if the calculator requires service.
Then, if necessary, read "If the Calculator Requires Service" on page
151.
B If the calculator won't turn on (nothing is visible in the display):
1. Attempt to reset the calculator (see page 146).
2. If the calculator fails to respond after step 1, replace the bat-
teries (see page 143).
If steps 1 and 2 fail to restore calculator function, it requires service.
B If the calculator doesn't respond to keystrokes (nothing hap-
pens when you press any of the keys):
1. Attempt to reset the calculator (see page 146).
2. If the calculator fails to respond after step 1, attempt to clear
memory (see page 146). This will erase all the information
you've stored.
A: Assistance, Batteries, Memory, and Service 147