I just received my December batch L3+ today and when I opened it and took out the miner, if I turn it upside down, I hear something moving around inside. This can't be good, right? I will test more shortly once I get home from work.
The sound is your hashboards. They do make a rattle noise. I wouldn't jostle them around too much like turning them "upside down". You may knock a Heat Sync off.