Unresponsive Photon: no LED

I have a photon shield connected to a battery shield that I set in an enclosure and let drain overnight. It was working (flashing green) last night and when powered via USB now, has become completely unresponsive (no LED, can not change modes, can not detect serial or USB connection). Is it bricked? Has anyone encountered anything like this?

it might just need to be more fully charged.

Once fully charged, the green blinking light comes on but the device is still unresponsive to anything. I can’t put into DFU or safe mode, and it isnt even recognized as a serial port connection when directly connected via USB

i’m not sure but my first guess would be a bad bootloader which if so you will need to flash a new one. but, there are many more knowledgeable than myself
so hopefully some one can help.

Sorry, which components stick togehter with which firmware?

@byou, if you have a multimeter, take your photon out of the battery shield and connect it to USB. Then measure the 3V3 pin to make sure the voltage is 3.3v. If that is good, you may need to reflash everything to the Photon as it may have been wiped by the low power condition. If you don’t have a JTAG programmer but you have an extra Photon, you can follow these instructions:

I have an unresponsive Photon. Used to work, don’t recall doing anything “bad” to it…

No LEDs.
3V3 measures 3.25V
Metal heat sink appears flat and not touching anything.
5V USB current is ~400mA and part/board gets pretty warm.

SWD says “SWD Protocol error”

Any other ideas?