Unique dead Samsung S7 scenario. Traditional advice doesn't apply.

[Sirgeorge]

I'll make it punchy for you: I've got an S7 that doesn't turn on. No notification lights, no sound, soft and hard reset key combos don't work, wireless charging is detecting that it's charging something, wired charging doesn't detect a device. IMMACULATE condition prior to this critical failure. What's happening and is there any use going through the process of popping the back off?

[Sirgeorge]

So I've done some further research and figured that, most likely, a component failed on the logic board and, less likely, a cable came undone. I'll update with info after I've pealed the back off.

[Jane]

First you can connect S7 to a laboratory power supply and check current consumption ( preferably with analogue ampermeter)
 when   power button ON and OFF.