Hi, This is my first post here, so sorry if this is in the wrong place. I have a problem that I hope you guys can help with. I have a number of Behringer Ultra-DI. For some reason these DI's no longer work with phantom power but when a 9 volt battery is inserted it is fine. I assume that the phantom power section of it is blown. I was wondering what would cause this ( it has happen to about 4 DI's)? And if it can be fixed? And whether it is worth it? Cheers For a little background- They are used for keys, bass, acoustic guitar.