I encountered the same problem, and have been having an awful experience with the Advanced Resolution Group and particularly Gerard James. I am planning to get our company off Dell, too. Amazing that they are fine with saving a few bucks while at the same time loosing 10s of thousands of dollars that we will be spending elsewhere.
Same problem here. I have also had awful experiences with the Advanced Resolution Group. My wish is that the class action lawyers will descend on us, take up the issue, and get some justice for us over this defective product and awful service. One can dream.
I have this dreaded problem too, and the Advanced Resolution Group and tech support have not been able to resolve it after at least 3 attempts. What do you suggest as a next step? It truly is unusable and unsalable.
To my opinion, the the noice is produced by the DELL power adapter. I try to find an universal adapter working with the XPS 15 and hope to work noice free, like when there is no adapter connected.
I also have this problem. It's super annoying and comes from the power button area. If I put pressure against the casing in different ways (like the side of the monitor), the sound stops, but it continues as soon as I release. It's really annoying.