You can try downloading and installing NVidia Inspector and checking the fans. It's possible that there's a vBIOS problem and this will allow you to override that using an actual NVidia product to do so.
http://www.guru3d.com/files-details/...-download.html
You could also check to see if it's a static charge in a capacitor that's causing it. Unplug your system from the wall, press and hold the power button on the machine for 30 seconds to drain the capacitors. When you do this you might want to open your tower and reseat your GPU just to be sure.
Let me know if any of this works.