Looks good and I would get one if it get cheaper.
But for the moment I am ok with manually brushing the surface and sucking the dust with vacuum cleaner not touching the circuitry.
try memtest, you can run it in boottime just before windows will get loaded, make a thorough test and see what you get.
secondly, try HDD test, you may slave your drive to another computer and do CHKDSK /F
thirdly, make visual inspection...
If you haven't tried isolation try the following:
1. remove other components like extra ram and video card specially if you have multiple then start your computer and see if there is any changes.
2. remove more components until the...