Last week I cleaned my components inside the case (except the drives' cables) and today after I had a power-cut a strange noise (which existed a bit for the last couple of years) started and is now more common.
I randomly hear it meaning I doubt its coming from fan's noise. It goes like tik tik tik tik and last for half second, then goes away and occurs every 3 seconds ( like a clock ticking or a mouse in your closet)
In addition, I usually hear it when I do tasks like accesing program files or opening new tabs in firefox and just a little less frequently when my PC is idle.
its your hard drive's ummm reading arm (or something)
nothing to worry about realy (i had a computer - click on any thing tiktiktiktiktik lasted for years only died cause the psu died i wonder what i left on it O.O)
um no as they have no moving parts O.O
and ssd are expensive
and its not realy anything to worry about that 6.7gb hard drive i talked about is still working despite doing all the clicking (and has been for over 10 years)