Over the last couple of weeks I have noticed that my DVR has started making a annoying humming sound. It sounds as if the harddrive is getting ready to sizzle, smoke, and leave me with a melted hope of recovery TV shows that I love to watch.

However, nothing has been impacted at all just makes the noise. I powercycle and it goes away for a day or two but comes back eventually and doesn't go away until another powercycle. 

Anyone else having this trouble? 

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I have a definite answer on this.  I had the exact same issue with my desktop pc.

Here it is:

for any electronic device that has a fan (almost all do), a solid mount is critical.  If you have your dvr on top of another device, move it to be alone on a solid suface.  It's really not a good idea to stack devices as heat can be an issue and fry both stacked devices.  Your dvr is either just vibrating as it might not have a solid base to sit on or the hard drive is loose inside.

I would suggest first moving the dvr to be alone on a solid surface.  That alone will most likely fix the hum.  If it doesn't, your hard drive inside is loose and might be time for a call to att to replace it.

btw…my pc had a very solid mounted hard drive, but I broke a clip on the cover when putting back together.  Every now and then I need to push on the back of the broken cover…sound stops right away.

 Good luck.  Let me know if this fixes it?