There is no light, there are no “tones’, just a brick.
And yes, I’ve tried new cables, new charger blocks everything.
It was working perfectly until I tried to move it to antoher location. Even when I moved it back, it’s just dead. There was a little buzzing and the camer has a warm spot. Any ideas?
If that’s the case, I would suspect a power surge.
The new adapters you tried, those were not plugged in at all before and are at least 1A (1000mA) rated?
Often times the adapter is a “sacrificial lamb” and can save the device beyond it, but it is hit or miss and depends quite a bit on the design of the adapter.
So just to confirm, when plugging them in and not pushing any button, you get no light (steady or flashing) at all?
If 3 out of 4 cams all started doing that at the same time, I can’t think of anything other than a power surge (whether direct or possibly ESD from a nearby lightning strike that got in to the USB cables or cams) that would have caused that symptom.
Even if they all updated firmware and it failed, they should at least get a light when powering on.
Did you try holding the setup button for 30 seconds while plugging a cam in (factory reset)? I don’t see why that would work if you get no lights at all, but definitely worth a shot. If that seems to get some sort of response, you could try the manual firmware update procedure just to see if it was a bad firmware update (maybe power blipped while in progress).