Today I started my desktop normally and after a few seconds my fan proceeded to make strange noises. I don't know how to describe them other than to say the sound is not constant. I have a xfx 6870 where the fan failed once and the whole fan heatsink assembly was replaced about 2 months ago. The fan would make very little noise compared to my case fans but now it makes a a sort of wub wub noise. The fan itself is spinning and does not come in contact with the assembly. After taking it out and dust the fan and case I noticed another problem. After startup, the rig would run normally then suddenly lose power, and then suddenly regain power after which the video card would start being noisy. The computer goes to the windows 7 login screen just fine. What is wrong here?
I use speedfan. Idling, local temp is 25 C, cores (i7 860) idle at 30-35C, GPU at 35-39 C. Also, on the most recent startup no sudden power loss was observed and the fan started off normally and became loud and obnoxious during windows startup. Current RPM: ~2000.