I know there are similar posts but not like this.
I have 5 Photons and have always managed setup with the iPhone app. But I downloaded a newer version & there was no obvious click to even get to setup (listed my Photon, though). So after teeth gnashing I moved to USB setup. Of course, I had to download particle app. Text copy from Terminal below represents my Nth try (for large N):
$ particle setup (Photon blinking blue) _ __ _ _ _ | '_ \ __ _ _ __| |_(_) ___| | ___ | |_) |/ _` | '__| __| |/ __| |/ _ \ | __/| (_| | | | |_| | (__| | __/ |_| \__,_|_| \__|_|\___|_|\___| https://particle.io > Setup is easy! Let's get started... > It appears as though you are already logged in as *** ? Would you like to log in with a different account? No ! PROTIP: Hold the MODE/SETUP button on your device until it blinks blue! ! PROTIP: Please make sure you are connected to the internet. > I have detected a Photon connected via USB. ? Would you like to continue with this one? Yes ! The Photon supports secure Wi-Fi setup. We'll try that first. ! PROTIP: Wireless setup of Photons works like a wizard! ! PROTIP: We will automagically change the Wi-Fi network to which your computer is connected. ! PROTIP: You will lose your connection to the internet periodically. ? Found "Photon-***". Would you like to perform setup on this one now? Yes ! PROTIP: You will need to know the password for your Wi-Fi network (if any) to proceed. ! PROTIP: You can press ctrl + C to quit setup at any time. ! You are still connected to your Photon's Wi-Fi network. Please reconnect to a Wi-Fi network with internet access. ? Have you reconnected to the internet? Yes > Obtained magical secure claim code. > Hey! We successfully connected to Photon-*** > Now to configure our precious Photon-*** ! PROTIP: If you want to skip scanning, or your network is configured as a ! PROTIP: non-broadcast network, please enter manual mode to proceed... ? Would you like to manually enter your Wi-Fi network configuration? No ▄ Asking the Photon to scan for nearby Wi-Fi networks...events.js:161 throw er; // Unhandled 'error' event ^ Error: connect ECONNREFUSED 192.168.0.1:**** at Object.exports._errnoException (util.js:1023:11) at exports._exceptionWithHostPort (util.js:1046:20) at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1090:14) =============
So this ends with an error message & dumps me back in the Shell. But perversely, my Photon went to breathing cyan. Why?