Quote Originally Posted by Rambozo View Post
All inverters run at high switching frequencies inside. Sometimes that can result in a very high pitched squealing. Typically it is from the laminations on inductors vibrating. While it can be annoying, it doesn't really do any harm. Sometimes rough handling during shipping can make it more of an issue. You have a few options depending on how loud it is and how much it bothers you. You can call Everlast about it, and see what they say. You can check the unit inside to make sure there isn't any obvious shipping damage and all the bolts are tight. You can also apply potting compound to the inductors, if that is the problem. That material is available in spray cans at electronic shops. Also make sure nothing is touching the case and setting up vibrations.
Ill have to talk to everlast and see about your recommendation, thanks for the advice