That unit has a 7 year warranty, so if you think it has an issue, contact Seasonic for an RMA.
http://www2.seasonic.com/product/x-650/
I had a monitor which started making high pitched noises after a couple of years. it turned out to be one of the capacitors (looks a bit like a drinks can) on the power supply board. moisture gets into the caps over time, and the metal tops of them start 'bulging'. it was a £2 part, just needed a screwdriver for the monitor casing, a solder sucker and a soldering iron. (if you replace a cap, if it's polarized, make sure you get positive and negative leads right)
bought it in 2013 july but it now does not make noise it is just random so how will they check it?
bought it in 2013 july but it now does not make noise it is just random so how will they check it?