Here are the operational and non-operational (storage) condition
specifications for the Macintosh Plus:
Temperature
-----------
Degrees Degrees
Fahrenheit Celsius
---------- -------
Operating 50 to 104 10 to 40
Storing -40 to 122 -40 to 50
Humidity
--------
All conditions: 5% to 90% relative humidity
Altitude
--------
0 to 4615 meters
0 to 15,000 feet
If you expect the Macintosh Plus to be at -40 (F or C) for a long period,
especially if there are occasional dips significantly below -40 degrees,
you may encounter some, all, or none of these conditions:
- Possible thermal stress of the electrolytic capacitors to the extent
that they crack, leak, or fail when thawed.
- Possible thermal stress of the fiberglass/epoxy resin of the circuit
boards, leading to hairline fractures of the printed circuit board.
- Possible thermal stress of the CRT, leading to hairline fractures of the
glass.
- Possible thermal stress of the cables inside the Macintosh Plus, leading
to hairline fractures of the insulation or conductor.
- Possible thermal stress of the junctions inside the integrated circuits
caused by the variation in thermal expansion of the plastic case and the
metal wires.
Any of these scenarios can lead to failure of one or more parts of the
system. We recommend that you keep the Macintosh Plus in a closet or in
some other heated living quarters. If this is not an option, after
removing the system from this extreme temperature, allow the Macintosh
Plus to return to a normal operating temperature slowly, possibly over a
period of days. By allowing the components to warm gradually, if there
hasn't been any irreversible damage, the system should be fine.
If the capacitors have cracked, you may notice some fluid dripping down
the left side of the case or some discoloration in this area. In that
case, or if the system behaves erratically or you hear crackling or
popping on startup, shut down the system immediately and take it to your
authorized service center for examination.