It's coil whine and not fan noise from the PSU, then? If the latter, replace the fan. It's not that hard to do. Heck, your warranty has expired. You can experiment. If it turns out to be coil whine, you can try putting non-electrically conductive epoxy or RTV on the coils to stop the buzz.
I'm not really familiar with how coil whine sounds, so I'm not sure if that's what it is.http://www.youtube.com/user/majiktheory ... p_axOyd1Z8
- would that be an example of coil whine? If so, it's not quite what I'm hearing.
At any rate, you of course have a very good point about simply replacing the fan. I'll definitely look into that. I have never disassembled a PSU unit before, so I didn't consider it at first.
I will also be building a new desktop very soon (next week or the week afterwards) and I'll try to carry over the 620HX in order to see if it might be interferance with other components in my current desktop that is causing the issue. I'll try giving it a thorough cleaning as well to see if that helps.