Lenovo laptop fan sound

peenacdey

Honorable
Dec 31, 2013
1
0
10,510
i bought a brand new laptop yesterday, . Lenovo 505s(apu quad core 10) 8gb ram ,etc
...
sometimes, there is a "trrrrrr" sound coming out of the laptop fan. ,not always, ..sometimes its really low and inaudible, sometimes its loud enough to hear...

I downloaded some disk check tools/ultilities, even the best ones, they all claimed my laptop hard drive are in good and normal condition ...

even the disk health check utility In windows 8 ( dos prompt ) claimed that my hard drive is fine.

..........
what seems to be the problem? why is the fan making a "trrrr" noise?