That would be normal, as the variable speed fan comes on only when the computer is under load.
What is not normal is that the fan is not coming on when the computer
overheats.Or that the fan is not cooling enough when computer is
Monitor computer temperature using a software, check if Fan is coming up when temperature gets critical.
If fan comes up but does not cool enough, then replace the fan, it is
not efficient anymore because of a bad bearing or dust. ~Also ensure
that fan is well mounted, if fan has poor contact with CPU surface ,
cooling will be poor.
If fan does not come up, and critical temp is not detected, then the
sensor on motherboard is bad, this is very uncommon. When this happens
the problem is usually related to system or power settiings , rather
If fan does not come up and temp is critical, then fan is faulty, replace it.
There are also more than one fan on many laptops, check that one of the
fans (CPU fan, video fan) is not completely ded, and therefore cause
for the problem.
By using the software below you can also find out if the problem is
really overheating. If temperature results within normal range, then
usually it is not overheating.In that case test systtem and check power
Here is the software to control your fan and temp. sensor state:
Download SpeedFan - Access temperature sensor in your computer
Download SpeedFan 4.38
SpeedFan - Free software download