Yeah it suck when stuff like that happen, but at least Street guardian have the best service and customer care, only reason you haven't tasted that already are probably that it is Saturday, normally they are all over a case in here, and usually in minutes.
The memory cards i had die on me was all brand high end extreme cards, the most expensive ones i ever gotten at the time, and i dident even get to fill up the 64 GB cards once
but Amazon was nice and had a new card in my mailbox almost faster than i was in shipping out the broken one.
I think if the camera get enough power to boot, then it are probably not the PSU that's the problem, but it is something people can try out, i cant say i have heard of many if any SG power supplies dying in here.
I had a GPS antenna die on me on a SG camera, but as it was on one of a few free test cameras i would not bother them with that, and with 5 cameras on my windscreen even if one do not have GPS speed i can live with that.
One other guy had the same a year or two back, he got a new working GPS sent out right away, so me and him are a pretty exclusive club.
Some times customers have tried a hard wire kit from a old install, or maybe use some USB plug in the car ( which pretty much all have too little power for a dashcam )
BTW i just recalled my SGGCX2 ( old version ) also threw a fit one day, but i just flashed the firmware again and then its been working just fine since then, and this was in April or something last year.
But i cant recall if it was acting up like yours do, or if it was some other unwanted behavior.
I think warranty cameras most often go out from Jon, he are set up in Carson city in Nevada as i recall, normally it seem a new camera are only 1 working day to reach customers.