I have a Photon that was working well, but suddenly quit working.
The symptoms are somewhat odd, and I think that it is a hardware failure.
a) The Photon was driving a 1.8" TFT display used as a thermometer display.
b) Suddenly the display stopped updating, and a reset resulted in a blank but illuminated screen.
c) Replaced the display, same problem.
d) Reflashed the software. Photon gets updated fine, breathes cyan normally after sending the firmware. Screen still blank.
e) Reset and reflashed. Same problem.
f) Replaced in circuit with different Photon, flashed new Photon with same software, display works normally.
g) Tried the old (bad) Photon back in the circuit, reflashed several times, display does not work.
So basically I have one Photon that works fine and another that does not work when placed in the same circuit and flashed with the same firmware.