# Photon flashing yellow

**URL:** <https://community.particle.io/t/photon-flashing-yellow/46587>\
**Category:** Troubleshooting\
**Tags:** photon\
**Created:** [December 27, 2018, 11:09pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587 "2018-12-27T23:09:42Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [December 27, 2018, 11:09pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/1 "2018-12-27T23:09:42Z")

</div>

After working for weeks, my photon suddenly began flashing yellow. It doesn't connect to the wifi any more without changing anything on the particle itself.  
Now, I wanted to go into the safe mode (cyan breathing). This is unfortunately impossible: if I follow the steps described, it flashes 5x cyan and then flashes again yellow.  
I read this: [[SOLVED]Flashing yellow](https://community.particle.io/t/solved-flashing-yellow/17653)

But it doesn't help. I installed on a mac particle cli, but I cannot flash a firmware.  
In general, I cannot change the photon's mode. I assume yellow flashing is DFU mode, so I should be able to connect it to the mac and flash right away, but I get:

> particle serial list  
> No devices available via serial

How can I get my photon running again?

---

<div class="post-metadata">

**Author:** ![nrobinson2000](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/nrobinson2000/32/15624_2.png) [@nrobinson2000](https://community.particle.io/u/nrobinson2000)\
**Post date:** [December 27, 2018, 11:32pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/2 "2018-12-27T23:32:44Z")

</div>

Do you have dfu-util installed?

It sounds like you may need to re-flash the system firmware.

Can you confirm if the photon is listed in dfu?

Try the following command:

```auto
dfu-util -l

```

There is a command included in Particle CLI that can re-flash system firmware. Can you try the following when the photon is connected and in dfu mode?

```auto
particle update

```

---

<div class="post-metadata">

**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:** [December 28, 2018, 1:21am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/3 "2018-12-28T01:21:39Z")

</div>

To compliment what @nrobinson2000 has already mentioned and to clarify:

> [@black\_a](#):
>
> I wanted to go into the safe mode (cyan breathing).

Cyan breathing is normal operation, cloud connected. Breathing Magenta would be Safe Mode.

> [@black\_a](#):
>
> But it doesn’t help. I installed on a mac particle cli, but I cannot flash a firmware.
> 
> In general, I cannot change the photon’s mode. I assume yellow flashing is DFU mode, so I should be able to connect it to the mac and flash right away, but I get:
> 
> > particle serial list
> > 
> > No devices available via serial

In DFU mode, you cannot use a serial connection. For that it would have to be in listening mode (blinking blue). The `particle update` mentioned above _should_ work in DFU mode.

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [December 28, 2018, 8:18am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/4 "2018-12-28T08:18:23Z")

</div>

Thank you for the quick reply!  
To clarify, I attached a video of the blinking. I have dfu-util installed.  
Video:

[Video blinking](https://www.dropbox.com/s/a477bfbiuqmc6pk/IMG_0543.MOV?dl=0)

The command gives me:

```auto
Deducing device DFU version from functional descriptor length
Found Runtime: [05ac:828f] ver=0149, devnum=6, cfg=1, intf=3, path="20-3.3", alt=0, name="UNKNOWN", serial="UNKNOWN"

```

No matter if the photon is connected or not.

particle update gives me:

```auto
!!! 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.

```

Sorry, I have to correct: it is flashing 5x magenta, not cyan, upon being connected to the power or when I try to enter dfu mode via the buttons.

---

<div class="post-metadata">

**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:** [December 28, 2018, 9:46am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/5 "2018-12-28T09:46:04Z")

</div>

A 3sec video isn’t always telling the whole story. If you could take a video (~30sec) with your device **_out_** of the breadboard and from plugging it in to a few cycles of the flashing yellow, that would be more helpful.

This could be a combination of issues involving the power supply, the cable, the SETUP button, your code, …

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [December 28, 2018, 11:32am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/6 "2018-12-28T11:32:58Z")

</div>

[Here](https://www.dropbox.com/s/d5ukiekhn8gjqnu/IMG_0544.MOV?dl=0) a new video. I plugged in, then the magenta light, then the yellow light. Then I plugged it out, and plugged it in again and the whole procedure starts over.

---

<div class="post-metadata">

**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:** [December 28, 2018, 12:40pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/7 "2018-12-28T12:40:06Z")

</div>

This very much looks like a power issue, that's why I suggested this ...

> [@ScruffR](#):
>
> with your device out of the breadboard  
> [...]  
> This could be a combination of issues involving the power supply, the cable, the SETUP button, your code, …

Take the thing out the breadboard, change the USB cable and the power supply and test again.

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [December 28, 2018, 11:12pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/8 "2018-12-28T23:12:09Z")

</div>

I just did this (removed from bread board, removed all cables, new usb cable, new power source) - no change. Still exactly the same problem / lights flashing

---

<div class="post-metadata">

**Author:** ![mstanley](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/mstanley/32/20170_2.png) [@mstanley](https://community.particle.io/u/mstanley)\
**Post date:** [December 29, 2018, 2:05am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/9 "2018-12-29T02:05:21Z")

</div>

Hey Black,

What is the power source you are using to power this device with? Is it using a wall wart directly into the wall? Or is it being powered by a computer via USB or a USB hub?

That behavior is very unusual and not anything I’ve seen before. My first instinct is to think this is a power related issue as well

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [December 29, 2018, 9:00am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/10 "2018-12-29T09:00:05Z")

</div>

I used a wall connector, USB hub and a professional power supply unit. My measurements: while it is flashing magenta, it consumes 12mA @5.0V, when is enters the yellow blinking state 18mA.

Please not that the video was taken with a mobile camera, so that the flashing may (due to bad FPS rates) look different in the video than it does in reality. The magenta for example in the beginning is the normal magenta breathing.

Also, when look for reasons to solve that: I barely assume that is has do with the code: the chip was doing a simple routine task and sleeping most of the time for weeks, until this happened suddenly.

---

<div class="post-metadata">

**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:** [December 29, 2018, 10:39am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/11 "2018-12-29T10:39:30Z")

</div>

> [@black\_a](#):
>
> a professional power supply unit

Make sure you haven't set the current limiter too low.  
18mA while breathing magenta seems to be on the low side - I'd rather expect it to be somewhere around 80mA - 18mA is stated as the typical current draw in powersafe mode, which shouldn't be the case when entering normal WiFi operation or Safe Mode.

 ![image](https://us1.discourse-cdn.com/flex026/uploads/particle/original/3X/8/a/8afa3fa1c008be6378f4d35e9c5bdb2d6142b540.png)

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [December 29, 2018, 11:23am UTC](https://community.particle.io/t/photon-flashing-yellow/46587/12 "2018-12-29T11:23:07Z")

</div>

Thank you for the table! The limit is at 3A so there shouldn’t be any conflict… So this would indicate that the chip is in powersave mode? Is there a trick to force wake him?  
This may really be a possibility as the chip was in powersave mode most of the time so it may have gotten stuck.

---

<div class="post-metadata">

**Author:** ![mstanley](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/mstanley/32/20170_2.png) [@mstanley](https://community.particle.io/u/mstanley)\
**Post date:** [December 29, 2018, 8:18pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/13 "2018-12-29T20:18:07Z")

</div>

If it were in powersave, presumably the LED should be off entirely. Based on the video you provided, it seems to be in some weird state where there are long pauses of the LED off in between safe mode and DFU mode. Those off-state pauses are very unusual.

Userland code can cause complications, so it isn’t unreasonable to think it could be causing complications.

Are you able to get a consistent flashing in yellow if you intentionally try to put it into DFU (holding MODE, and pressing reset)? Or does it continue to do the off/on alternating?

If you can get it into a consistently flashing yellow, I’d definitely recommend you to try and reflash the device OS and Tinker to the device to see if the behavior persists.

If you aren’t able to get a connection in DFU mode, also double check your cable. It is possible the cable may not have a data line.

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [January 29, 2019, 7:50pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/14 "2019-01-29T19:50:53Z")

</div>

> [@nrobinson2000](#):
>
> particle update

I re checked all possibilities: the cable has a data line (it's the official one from particle), do you mean by holding MODe and pressing reset this:

> 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.

Because that's what I try but doesn't work.

I always get:

> ` particle update`
> 
> !!! 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.

Any other ideas? I can exclude that it is user-land code there was only very basic code running.

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [January 29, 2019, 8:04pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/15 "2019-01-29T20:04:37Z")

</div>

P.S. I get the following:

`particle serial list`

> No devices available via serial

`

---

<div class="post-metadata">

**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:** [January 29, 2019, 8:06pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/16 "2019-01-29T20:06:10Z")

</div>

> [@black\_a](#):
>
> the cable has a data line (it’s the official one from particle)

Cables can break. Have you tried another one?

Can you put the device into Listening Mode to reflash the bootloader?

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [January 29, 2019, 8:17pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/17 "2019-01-29T20:17:32Z")

</div>

I can flash my other microcontrollers with this cable. It really works.

You mean by pushing for 3s the setup button? No, I can’t. It always behaves exactly as described above (breathing cyan, then flashing quickly yellow) no matter if I push the setup button or not.

---

<div class="post-metadata">

**Author:** ![nrobinson2000](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/nrobinson2000/32/15624_2.png) [@nrobinson2000](https://community.particle.io/u/nrobinson2000)\
**Post date:** [January 29, 2019, 8:18pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/18 "2019-01-29T20:18:53Z")

</div>

> [@black\_a](#):
>
> breathing cyan, then flashing quickly yellow

Really? Could you post a video?

---

<div class="post-metadata">

**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:** [January 29, 2019, 8:22pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/19 "2019-01-29T20:22:03Z")

</div>

Your video link has expired, can you reupload a video (also showing the attemt to enter Safe Mode & Listening Mode)?  
Does this also happen when you power the device from a wall wart?  
When you do the RESET/SETUP button business you _never_ see any magenta at all?

---

<div class="post-metadata">

**Author:** ![black\_a](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@black\_a](https://community.particle.io/u/black_a)\
**Post date:** [January 29, 2019, 8:45pm UTC](https://community.particle.io/t/photon-flashing-yellow/46587/20 "2019-01-29T20:45:37Z")

</div>

see here:

1. [switching simply on](https://www.dropbox.com/s/ckqp0t8qecjvpsb/switching%20on%20trial.m4v?dl=0)
2. [trying to enter listening mode](https://www.dropbox.com/s/2b2ru134qxmb8p8/listening%20trial.m4v?dl=0)
3. [trying to enter dfu mode](https://www.dropbox.com/s/0dxbg4bddl8vdgv/dfu%20trial.m4v?dl=0)

Please note that the yellow flashing is in reality very fast; due to the FPS rate of the camera, it appears slower.

[Next page](https://community.particle.io/t/photon-flashing-yellow/46587.md?page=2)
