# Xenon stuck in DFU mode **URL:** \ **Category:** Troubleshooting\ **Tags:** xenon\ **Created:** [March 21, 2019, 6:48am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571 "2019-03-21T06:48:54Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 21, 2019, 6:48am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/1 "2019-03-21T06:48:54Z")
I was flashing my Xenon with code, setting it into DFU mode before flashing. Then after thinking that I had correctly flashed the device I noticed that it was still flashing yellow. Nothing I’ve done has been able to get it out of this state. I’m on the 0.9.0 firmware. What do I do now? The Xenon had been working fine for quite some time otherwise. ---
**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:** [March 21, 2019, 10:06am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/2 "2019-03-21T10:06:33Z")
> [@pierrep](#): > > Nothing I’ve done has been able to get it out of this state. To spare us from having to suggest things you've already tried: what have you tried already? Particle update and Particle flash --usb tinker, is mostly a good way to start. ---
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 22, 2019, 12:41am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/3 "2019-03-22T00:41:24Z")
Thanks. The Xenon no longer appears as a serial device, so none of that works. I had already tried the “particle flash --usb tinker” command. ```auto particle update Physically unplug and reconnect the Particle device and try again. !!! There was an error trying execute DFU utilities. !!! For help with installing DFU Utilities, please see: https://docs.particle.io/guide/tools-and-features/cli/#advanced-install !!! You may also find our community forums helpful: https://community.particle.io/ > Error code: unknown ``` Also: ```auto particle flash --usb tinker Physically unplug and reconnect your Particle devices and try again. Error writing firmware: Missing permissions to use DFU ``` I have the requisite udev rules to access the device without being root. I’m on Ubuntu Linux btw. ---
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 22, 2019, 1:04am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/4 "2019-03-22T01:04:52Z")
OK if I plug the xenon that’s stuck with a flashing yellow led I get this in the system logs: ```auto kernel: [2805.618044] usb 3-2: new full-speed USB device number 10 using xhci_hcd kernel: [2805.767533] usb 3-2: New USB device found, idVendor=2b04, idProduct=d00e, bcdDevice= 2.51 kernel: [2805.767540] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 kernel: [2805.767544] usb 3-2: Product: Xenon DFU Mode kernel: [2805.767548] usb 3-2: Manufacturer: Particle kernel: [2805.767551] usb 3-2: SerialNumber: e00fce68a65eef6f7fb0d535 ``` One of my other xenons that is healthy enumerates like this: ```auto kernel: [2839.143260] usb 3-2: USB disconnect, device number 10 upowerd[1306]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-2 kernel: [2843.911104] usb 3-2: new full-speed USB device number 11 using xhci_hcd kernel: [2844.061157] usb 3-2: New USB device found, idVendor=2b04, idProduct=c00e, bcdDevice= 1.01 kernel: [2844.061163] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 kernel: [2844.061167] usb 3-2: Product: Xenon CDC Mode kernel: [2844.061171] usb 3-2: Manufacturer: Particle kernel: [2844.061175] usb 3-2: SerialNumber: e00fce682d03364c5ddb3518 mtp-probe: checking bus 3, device 11: "/sys/devices/pci0000:00/0000:00:14.0/usb3/3-2" mtp-probe: bus: 3, device: 11 was not an MTP device kernel: [2844.076040] cdc_acm 3-2:1.0: ttyACM0: USB ACM device kernel: [2844.076519] usbcore: registered new interface driver cdc_acm kernel: [2844.076520] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters upowerd[1306]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-2 upowerd[1306]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-2/3-2:1.1 upowerd[1306]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-2/3-2:1.0 ``` How do I get the first device out of this state? ---
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 22, 2019, 1:08am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/5 "2019-03-22T01:08:10Z")
I also tried ```auto particle flash --usb hybrid-0.9.0-xenon.bin Physically unplug and reconnect your Particle devices and try again. Error writing firmware: Missing permissions to use DFU ``` Same problem. ---
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 22, 2019, 1:18am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/6 "2019-03-22T01:18:28Z")
I can use dfu-util though, here’s the output of dfu-util --list ```auto Found DFU: [2b04:d00e] ver=0251, devnum=14, cfg=1, intf=0, path="3-1.3", alt=2, name="@External Flash /0x80000000/1024*004Kg", serial="e00fce68a65eef6f7fb0d535" Found DFU: [2b04:d00e] ver=0251, devnum=14, cfg=1, intf=0, path="3-1.3", alt=1, name="@DCD Flash /0x00000000/1*016Ke", serial="e00fce68a65eef6f7fb0d535" Found DFU: [2b04:d00e] ver=0251, devnum=14, cfg=1, intf=0, path="3-1.3", alt=0, name="@Internal Flash /0x00000000/1*004Ka,47*004Kg,192*004Kg,4*004Kg,4*004Kg,8*004Ka", serial="e00fce68a65eef6f7fb0d535" ``` ---
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 22, 2019, 1:26am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/7 "2019-03-22T01:26:57Z")
Also I’m able to run ```auto sudo /home/username/bin/particle particle flash --usb tinker ``` This runs without error, but then nothing happens. ---
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 22, 2019, 1:40am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/8 "2019-03-22T01:40:51Z")
OK so this runs and gives the following output: ```auto dfu-util -d 2b04:d00e -a 2 -s 0x80200000 -D tinker-0.9.0-xenon.bin dfu-util 0.9 Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc. Copyright 2010-2016 Tormod Volden and Stefan Schmidt This program is Free Software and has ABSOLUTELY NO WARRANTY Please report bugs to http://sourceforge.net/p/dfu-util/tickets/ dfu-util: Invalid DFU suffix signature dfu-util: A valid DFU suffix will be required in a future dfu-util release!!! Deducing device DFU version from functional descriptor length Opening DFU capable USB device... ID 2b04:d00e Run-time device DFU version 011a Claiming USB DFU Interface... Setting Alternate Setting #2 ... Determining device status: state = dfuIDLE, status = 0 dfuIDLE, continuing DFU mode device DFU version 011a Device returned transfer size 4096 DfuSe interface name: "External Flash " Downloading to address = 0x80200000, size = 11140 Download [=========================] 100% 11140 bytes Download done. File downloaded successfully ``` I’ve also tried the firmware and factory reset specified here to no avail: [https://docs.particle.io/tutorials/device-os/led/xenon/](https://docs.particle.io/tutorials/device-os/led/xenon/) ---
**Author:** ![pierrep](https://avatars.discourse-cdn.com/v4/letter/p/43a26b/32.png) [@pierrep](https://community.particle.io/u/pierrep)\ **Post date:** [March 22, 2019, 2:51am UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/9 "2019-03-22T02:51:46Z")
Ok I finally fixed it. I created an empty project, flashed it in Debug mode and it seems to have returned to normal. Flashing my original code then worked after this step too. No idea why I would have to do this, nor why this would work. It feels like a bug. I’ve been able to reproduce this twice already. Usually flashing it with different code or different target (e.g. Flash application & DeviceOS (local)) seems to work…definitely buggy. I’m using the latest Particle workbench to flash my code. ---
**Author:** ![miroslav.petrov](https://avatars.discourse-cdn.com/v4/letter/m/f07891/32.png) [@miroslav.petrov](https://community.particle.io/u/miroslav.petrov)\ **Post date:** [January 8, 2020, 8:53pm UTC](https://community.particle.io/t/xenon-stuck-in-dfu-mode/48571/10 "2020-01-08T20:53:28Z")
Thank you! It worked for me!