I accidentally shorted the 3.3v pin in the Particle Photon with ground. Within a second a puff of smoke rose from the circuit board and the photon no longer worked - when I connected power nothing happened, no LEDs lit and no boot.
After a little looking around I discovered that the problem was likely the regulator which lowers the USB input voltage VIN down to 3.3V which all arduino like platforms use. When I connected a 3V battery module between the ground and 3.3v nothing happened but there was quite a large current draw.
I decided to bite the bullet and attempt a repair given that I basically had nothing to loose!
First I cut the pins on the regulator using a sharp craft knife carefully avoiding any collateral damage to other components. This left a blank spot on the board as shown below.
Figure1: Removal of broken regulator
I then tested the photon by connecting the 3v battery again. Success! the photon boot perfectly.
Next I ordered a DC 5V to 3.3V Step-Down Power Supply Module AMS1117-3.3 LDO 800mA from eBay. I connected it’s three pins up between ground, VIN and 3.3V.
Figure2: Bypassing with new regulator
It now works like new!