[SOLVED]Photon Hard Fault, Cannot connect via serial in DFU-Mode

Hello everyone,

I have looked around for a while in the forum now with no luck. It seems as though I have bricked my photon. It flashes a hard fault (SOS + 1 blink). I am on a Macbook Pro.

when I try particle flash --usb tinker I get:

running dfu-util -l

!!! I was unable to detect any devices in DFU mode...

> Your device will blink yellow when in DFU mode.
> If your device is not blinking yellow, please:

1) Press and hold both the RESET/RST and MODE/SETUP buttons simultaneously.

2) Release only the RESET/RST button while continuing to hold the MODE/SETUP button.

3) Release the MODE/SETUP button once the device begins to blink yellow.

Error writing firmware...No DFU device found

I have the Photon in DFU-mode; the particle-cli, and dfu-util installed.

Also, when I run dfu-util -l I get:

dfu-util 0.8

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2014 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to dfu-util@lists.gnumonks.org

Deducing device DFU version from functional descriptor length
Found Runtime: [05ac:821a] ver=0042, devnum=7, cfg=1, intf=3, alt=0, name="UNKNOWN", serial="UNKNOWN"

hopefully somebody knows what I am missing and can help me to reflash/reset my Photon. Thanks in advance!

Try running your CMD as administrator…

Have you tried Safe Mode?

I forgot to mention that I had tried running it as sudo/administrator.

It seems to immediately jump to fault after trying to put it in safe mode, I’m sure that’s not a good sign.

I’m on Win10, but for what it’s worth, I had the exact same issue, and it was a missing / bad driver. Searching also turned up bad USB cable or USB 3.0 port as possible issues.

I had the SOS + 1 blink on photon immediately upon powering and when trying to enter safe mode. Was able to enter DFU mode, flashing yellow, however dfu-util couldn’t find the device. In Windows device manager, saw “Photon DFU Mode” was missing a driver (although previously installed). I installed following Tutorial: Installing DFU-Driver on Windows [24 Feb 2015], I was then able to run particle update, and the Photon now behaves.

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Awesome! I have access to a win 10 machine, I’ll try it out in the morning. Good to hear that there might be a solution.

Thank you all so much for the help! Grahamm, your fix worked! My photon is back in business.