# Photon in RED SOS hard fault mode, unable to put into safe mode **URL:** \ **Category:** Troubleshooting\ **Created:** [April 30, 2016, 6:42pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556 "2016-04-30T18:42:49Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Breau](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@Breau](https://community.particle.io/u/Breau)\ **Post date:** [April 30, 2016, 6:42pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/1 "2016-04-30T18:42:49Z")
Hello. Photon has been working fine for months, suddenly stopped working. Goes into RED SOS Hard fault mode. Here is what I have tried so far. ENTERING SAFE MODE - Tried entering safe mode, holding down both buttons, releasing on magenta. Instead of breathing purple, it simply breathes white for a bit and then goes back to RED SOS. UPDATING FIRMWARE - I am able to enter DFU mode, so I tried $ particle update. It said the update was successful but the problem was not fixed. FACTORY RESET - Tried getting to the factory reset option, but the LED flashing cycle never gets past yellow flash. As in, I hold down both buttons, release reset, it flashes magenta, then flashes yellow, then… keeps flashing yellow. DOWNGRADING FIRMWARE - Downloaded an old version of the firmware, reverse flashed it (part 2 first, then part 1). Terminal said it was successful, however it doesn’t fix the problem. Any ideas? Here is a link to the SOS.bin file (dfu-util -d 2b04:d006 -a 0 -s 0x8000000:0x100000 -U SOS.bin) [https://gametechmods.com/../uploads/files/6917SOS.rar](https://gametechmods.com/../uploads/files/6917SOS.rar) Thanks! EDIT: video link in case anyone is curious what is happening [http://www.filedropper.com/photontrouble](http://www.filedropper.com/photontrouble) ---
**Author:** ![Moors7](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/moors7/32/588_2.png) [@Moors7](https://community.particle.io/u/Moors7)\ **Post date:** [April 30, 2016, 7:00pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/2 "2016-04-30T19:00:21Z")
> [@Breau](#): > > ENTERING SAFE MODE - Tried entering safe mode, **holding down both buttons** , releasing on magenta. Instead of breathing purple, it simply breathes white for a bit and then goes back to RED SOS. I'm hoping you mean "holding SETUP, pressing RESET", otherwise it's just reset... > [@Breau](#): > > FACTORY RESET - Tried getting to the factory reset option, but the LED flashing cycle never gets past yellow flash. As in, I hold down both buttons, release reset, it flashes magenta, then flashes yellow, then... keeps flashing yellow. Hmm... strange... I could've sworn that [this part of the docs](https://docs.particle.io/guide/getting-started/modes/photon/#factory-reset) mentioned that... ehm... there is no factory reset on the Photon 😉 > [@Breau](#): > > UPDATING FIRMWARE - I am able to enter DFU mode, so I tried $ particle update. It said the update was successful but the problem was not fixed. > [@Breau](#): > > DOWNGRADING FIRMWARE - Downloaded an old version of the firmware, reverse flashed it (part 2 first, then part 1). Terminal said it was successful, however it doesn't fix the problem. So, current system firmware doesn't work, old system firmware doesn't work. Perhaps it's thus not the system firmware, but... the user firmware. Could you try updating the CLI to the latest version and then doing `particle update` once more. Once that's done, put it in DFU once more and give `particle flash --usb tinker` a try. See if that works, and let us know? ---
**Author:** ![Breau](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@Breau](https://community.particle.io/u/Breau)\ **Post date:** [April 30, 2016, 7:05pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/3 "2016-04-30T19:05:39Z")
Yes, sorry for wording. I mean holding both buttons, releasing reset, and then releasing setup. Factory reset is when you wait through all the flash modes until it rapidly flashes white, and then you release setup. Perhaps no longer an option on newer firmware, was just remembering from doing it when I first got it. I have updated to the current version and then flashed tinker. The terminal said that the flash was successful, but the problem persists. Thanks for your help! ---
**Author:** ![Moors7](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/moors7/32/588_2.png) [@Moors7](https://community.particle.io/u/Moors7)\ **Post date:** [April 30, 2016, 7:10pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/4 "2016-04-30T19:10:24Z")
Have you double checked cables/power supply to make sure they haven’t gone bad? ---
**Author:** ![Breau](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@Breau](https://community.particle.io/u/Breau)\ **Post date:** [April 30, 2016, 7:15pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/5 "2016-04-30T19:15:18Z")
I’ve used 2 different cords on three different USB ports, as well as connected to a 5V power supply. Doesn’t seem to be the issue. ---
**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\ **Post date:** [April 30, 2016, 8:07pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/6 "2016-04-30T20:07:48Z")
> [@Breau](#): > > Factory reset is when you wait through all the flash modes until it rapidly flashes white, and then you release setup. Perhaps no longer an option on newer firmware, was just remembering from doing it when I first got it. Nope, there never was Factory Reset on the Photon - what you describe is the Factory Reset of the Core. ---
**Author:** ![Breau](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@Breau](https://community.particle.io/u/Breau)\ **Post date:** [April 30, 2016, 8:11pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/7 "2016-04-30T20:11:10Z")
Ah, guess I was wrong. Too bad though, factory rest would help a lot in this case, since the magical safe mode isn’t working… ---
**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\ **Post date:** [April 30, 2016, 8:13pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/8 "2016-04-30T20:13:42Z")
The problem why FR is not available on the Photon is the absence of external flash to hold the factory reset image. ---
**Author:** ![mdma](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/mdma/32/1924_2.png) [@mdma](https://community.particle.io/u/mdma)\ **Post date:** [April 30, 2016, 10:29pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/9 "2016-04-30T22:29:57Z")
Thanks for the dump file - I’ll load that up on a Photon on Monday and see if it’s anything to do with the flash contents. I’ll let you know. 😄 ---
**Author:** ![jvanier](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/jvanier/32/5542_2.png) [@jvanier](https://community.particle.io/u/jvanier)\ **Post date:** [April 30, 2016, 10:30pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/10 "2016-04-30T22:30:03Z")
> [@Breau](#): > > Any ideas? Here is a link to the SOS.bin file (dfu-util -d 2b04:d006 -a 0 -s 0x8000000:0x100000 -U SOS.bin) I will try flashing your image on one of my Photons and see if I can reproduce the crash. It would help me a lot to find the cause if you were able to send me your user application code as a private message. ---
**Author:** ![Breau](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@Breau](https://community.particle.io/u/Breau)\ **Post date:** [April 30, 2016, 10:36pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/11 "2016-04-30T22:36:19Z")
> [@Photon in RED SOS hard fault mode, unable to put into safe mode](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/9): > > Thanks for the dump file - I’ll load that up on a Photon on Monday and see if it’s anything to do with the flash contents. I’ll let you know. smile Appreciate it. Let me know if you need the user application code. My only other thought would be we might have shorted something while working on the hardware, in which case it might just be permanently bricked. We were pretty careful though... here's a video link to what the boot up sequence looks like, and some basic trouble shooting I did. [http://www.filedropper.com/photontrouble](http://www.filedropper.com/photontrouble) ---
**Author:** ![davecasey](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@davecasey](https://community.particle.io/u/davecasey)\ **Post date:** [June 2, 2016, 10:55pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/12 "2016-06-02T22:55:24Z")
Was this ever resolved? I am experiencing a strikingly similar issue. Particle was working, happily logging temperatures, blinking LEDs, etc. Now it just blinks red SOS followed by 1 red blink, then blinks white for a half second, then back to red SOS+1. If I try to put into safe mode, when I release setup during magenta blink, it immediately flashes white for 1/2 second, then goes into red SOS+1 npm update -g particle-cli put in dfu mode particle update System firmware update successfully completed! Your device should now restart automatically. You may need to re-flash your application to the device. Near the end of update, white flash followed by SOS+1. put back in dfu mode particle flash --usb tinker Download done. File downloaded successfully white flash followed by red SOS+1 USB cable seems to be fine, I used it to update another photon with no problem. Power supply seems to be fine, the other photon seems happy enough with it, anyway. Is there a next step? Thanks, -Dave ---
**Author:** ![Bspranger](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/bspranger/32/5725_2.png) [@Bspranger](https://community.particle.io/u/Bspranger)\ **Post date:** [June 28, 2016, 7:12pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/13 "2016-06-28T19:12:10Z")
I was finally working with my Photon again this weekend. It was running great and now I have the same issue as described. I tried flashing tinker via USB and it says it completed successfully but I still have the same sos issue. ---
**Author:** ![Bspranger](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/bspranger/32/5725_2.png) [@Bspranger](https://community.particle.io/u/Bspranger)\ **Post date:** [June 28, 2016, 10:31pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/14 "2016-06-28T22:31:31Z")
Are A0 and A1 5 volt tolerant on the Photon? ---
**Author:** ![Moors7](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/moors7/32/588_2.png) [@Moors7](https://community.particle.io/u/Moors7)\ **Post date:** [June 28, 2016, 10:37pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/15 "2016-06-28T22:37:04Z")
Should be in here: [https://docs.particle.io/datasheets/photon-datasheet/#i-o-characteristics](https://docs.particle.io/datasheets/photon-datasheet/#i-o-characteristics) ---
**Author:** ![Bspranger](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/bspranger/32/5725_2.png) [@Bspranger](https://community.particle.io/u/Bspranger)\ **Post date:** [June 28, 2016, 11:38pm UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/16 "2016-06-28T23:38:08Z")
I looked at this table but only got confused… are all analog inputs only 3.3 volt tolerant? ```nohighlight PERIPHERALS AND GPIO The Photon has ton of capability in a small footprint, with analog, digital and communication interfaces. Peripheral Type Qty Input(I) / Output(O) FT[1] / 3V3[2] Digital 18 I/O FT/3V3 Analog (ADC) 8 I 3V3 Analog (DAC) 2 O 3V3 SPI 2 I/O 3V3 I2S 1 I/O 3V3 I2C 1 I/O FT CAN 1 I/O FT USB 1 I/O 3V3 PWM 93 O 3V3 Notes: [1] FT = 5.0V tolerant pins. All pins except A3 and DAC are 5V tolerant (when not in analog mode). If used as a 5V input the pull-up/pull-down resistor must be disabled. [2] 3V3 = 3.3V max pins. [3] PWM is available on D0, D1, D2, D3, A4, A5, WKP, RX, TX with a caveat: PWM timer peripheral is duplicated on two pins (A5/D2) and (A4/D3) for 7 total independent PWM outputs. For example: PWM may be used on A5 while D2 is used as a GPIO, or D2 as a PWM while A5 is used as an analog input. However A5 and D2 cannot be used as independently controlled PWM outputs at the same time. ``` ---
**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\ **Post date:** [June 29, 2016, 9:23am UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/17 "2016-06-29T09:23:49Z")
> [@Bspranger](#): > > [1] FT = 5.0V tolerant pins. _ **All pins except A3 and DAC** _ are 5V tolerant (when not in _analog mode_). If used as a 5V input the pull-up/pull-down resistor must be disabled. _analog mode_ is only activated via `analogRead()` (or undocumented `pinMode(pin, AN_INPUT)`), so yes all pins (including A-pins, but not A3 and DAC/A6) are 5V tolerant. But don't use internal pull-resistors then. ---
**Author:** ![Bspranger](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/bspranger/32/5725_2.png) [@Bspranger](https://community.particle.io/u/Bspranger)\ **Post date:** [June 29, 2016, 10:38am UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/18 "2016-06-29T10:38:58Z")
That is how I read it originally, but I think that is wrong. Because in the table it lists all analog adc as 3.3 volt. And on the FT foot note it says 5V tolerant (when not in analog mode). So if you use any A pin as analog adc then it is only 3.3 volt tolerant. Can you confirm? ---
**Author:** ![Moors7](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/moors7/32/588_2.png) [@Moors7](https://community.particle.io/u/Moors7)\ **Post date:** [June 29, 2016, 10:42am UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/19 "2016-06-29T10:42:50Z")
> [@Bspranger](#): > > So if you use any A pin as analog adc then it is only 3.3 volt tolerant. Sounds about right, hence the "when not used in analog mode". ---
**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\ **Post date:** [June 29, 2016, 11:44am UTC](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556/20 "2016-06-29T11:44:56Z")
Yup! As @Moors7 said. Pins labled with A can pose as analog pins (when used in analog mode) or _digital_ pins when used in _digital_ mode and then they ARE definetly 5V tolerant. Otherwise you would lose all your PWM capable D pins too, since PWM is only 3.3V - but as said **_only when in that mode_**. So that interpretation is NOT wrong 😉 [Next page](https://community.particle.io/t/photon-in-red-sos-hard-fault-mode-unable-to-put-into-safe-mode/22556.md?page=2)