Operation Outside Specified Temperature Range; Keyboard Operation; Pressure Differences - Husky MP2500 Manual

9.1.3 Operation outside specified temperature
range
The MP2500 is specified for operation in the range -30°C to +60°C (-22°F
to +140°F). Operation at low temperatures restricts battery capacity and
slows LCD screen response time.

9.1.4 Keyboard operation

The standard keyboard has individual moving keys. If the keys seem stiff,
they may be fouling the keyboard overlay. This is particularly likely at the top
edge of the keys. Try removing and refitting the overlay. If you cannot refit it,
you need to fit a new overlay. If the overlay is not the problem, check to see
if the keyboard area is contaminated. If it is, the unit should be returned for
servicing, but you may be able to improve operation in the mean time as
follows.
If the keyboard is contaminated with a dry powder or dust, you may be able
to remove it by using a high pressure air-line.
If the keyboard is contaminated with a wet or sticky substance such as
coffee or grease, clean it carefully as described in section 8.1.
The optional membrane keyboard is impervious to normal dust, moisture,
and contamination. When dirty, it can be cleaned with a detergent solution.
Do not use abrasive cleaners, or solvents.

9.1.5 Pressure differences

As the case is sealed, under certain circumstances (such as change of
altitude) the interior of the MP2500 may develop a substantial pressure
difference compared with the environment. Loosen and then tighten the
battery cap.
60 H MP2500 System Developer's Guide
USKY