Almost every time I connect my Macbook Pro (Earlier 2011) to a second Monitor. It will generate small but very grinding noise (hard to ignore that noise unless I play songs or let the fan speed go over 4000). The Fan speed for the CPU is around 2000 and there is no other noise except it.
The noise stop quickly after disconnect the second monitor.
I found this out after I installed Samsung 830 SSD. Before, I guess the noise is cover by the other noises since most of the time the fans is running very fast and the hard drive also make noise before.
Any suggestion about how to fix it? Thank you.