As you haven't had a useful answer, and I hate seeing enquiries go unacknowledged, at least I would reply.
The only idea that came to me is that if your unit has been stored for some time, say a couple of years, it could be that there's a backup battery that stores settings that has gone flat. Otherwise, I have no idea what could be the problem, as you have said you've reset it.
Also, how loud is this white noise? A very gentle hiss, or a loud roar? If very quiet, could be a hardware or software failure that's stopping audio getting to the output. If loud, that points to a software failure that's screwed up digital audio data.
In either case, if you've checked any troubleshooting hints in the manual, you need go get a tech to look at it. It's not something we can diagnose remotely unless it's a common fault with an easy remedy.
S