Did I fry my Photon?

I have my Photon powered by a switching regulator, which, when I touched with my finger, I think killed my Photon. Now when I detach it from my circuit, and power by USB instead, the only thing that seems to work on the board is the blue D7 LED. The buttons don’t seem to affect it, and one of the 3 components close to GND and VIN gets very hot very quickly. The 3V3 outputs and 5V outputs still measure correctly, though. Can I save 'er?

Did you “squeezed” on the metal cover on the wifi module and resulted in some dent?

No, physically the Photon looks fine. And I wasn’t touching the Photon board at all when it stopped working. I’m pretty sure it’s the 5-pin regulator on the board (right next to GND) that’s “getting hot”.

I’m guessing that you switching regulator is not outputting a clean stable supply (ie lots of ripple) that caused the on board regulator to heat up.

When you power on with the USB cable, are you able to place it in DFU mode?

No, the buttons don’t seem to do anything. The RGB LED never lights up. Even with the USB instead, that on board regulator is heating up. Actually I just double-checked and my 3v3 line is reading 4.2v, where Vin reads 4.5.