# Updating Conbee II **URL:** \ **Category:** Dresden-Elektronik Hardware\ **Created:** [July 2, 2025, 7:57pm UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380 "2025-07-02T19:57:00Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![TDehli](https://forum.phoscon.de/letter_avatar_proxy/v4/letter/t/b4bc9f/32.png) [@TDehli](https://forum.phoscon.de/u/TDehli)\ **Post date:** [July 2, 2025, 7:57pm UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/1 "2025-07-02T19:57:00Z")
I have a Conbee WII that has been working nice for many years, but now I need to update to use a new thermostat. And then the problem has started… My deConz is version 2.24.1. I have tried to update to a newer version, but it is stuck at this version after innstallation. I think this might be because the conbee is not updated? The conbee is version 26650700. I have tried many versions of GCFFlasher, and tried to update to many different versions, but they all end in different crashes. One version does nothing. Another one fail after about a minute. And another one says “retry connect bootloader com5” Any good ideas, or will I have to give up using the new thermostatW? ---
**Author:** ![manup](https://forum.phoscon.de/user_avatar/forum.phoscon.de/manup/32/9_2.png) [@manup](https://forum.phoscon.de/u/manup)\ **Post date:** [July 3, 2025, 8:26am UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/2 "2025-07-03T08:26:15Z")
Can you please try to update with the approach described in [https://github.com/dresden-elektronik/deconz-rest-plugin/wiki/Update-deCONZ-manually#what-if-conbee-all-versions-still-refuses-to-flash](https://github.com/dresden-elektronik/deconz-rest-plugin/wiki/Update-deCONZ-manually#what-if-conbee-all-versions-still-refuses-to-flash) This should also work in harder cases, sometime switching to a different USB port may help too. ---
**Author:** ![TDehli](https://forum.phoscon.de/letter_avatar_proxy/v4/letter/t/b4bc9f/32.png) [@TDehli](https://forum.phoscon.de/u/TDehli)\ **Post date:** [July 3, 2025, 6:13pm UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/3 "2025-07-03T18:13:10Z")
I tried all the trick that was mentioned. Changing USB port didn’t help, and using parameter -x 3 gave no result either. They gave the same result; **Flash firmware** **command reset timeout** **retry connect bootloader com5** When trying to use the serial-number, I got the result that there was an invalid argument for parameter -s. I tried several versions of the flasher, with the same result. ---
**Author:** ![Mimiix](https://forum.phoscon.de/user_avatar/forum.phoscon.de/mimiix/32/10_2.png) [@Mimiix](https://forum.phoscon.de/u/Mimiix)\ **Post date:** [July 3, 2025, 7:20pm UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/4 "2025-07-03T19:20:03Z")
What file are you trying to flash? ---
**Author:** ![TDehli](https://forum.phoscon.de/letter_avatar_proxy/v4/letter/t/b4bc9f/32.png) [@TDehli](https://forum.phoscon.de/u/TDehli)\ **Post date:** [July 3, 2025, 9:50pm UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/5 "2025-07-03T21:50:13Z")
I am trying to flash deCONZ\_ConBeeII\_0x26780700.bin.GCF, which is the most recent version I have found. I have also borroved another conbee II, but the problem is the same. I have also found am old computer with windows 10, and installed deconz V2.30.02 I have tried flashing from this computer, but the result is the same. If I use older versions of GCFFlasher there is no response from the flasher. If I use v3.17 I get the message “retry,failed” If I use newer versions of the flasher I get “retry connect bootloader com5” I guess I am doing something wrong, since I have tried 2 computers, 2 sticks, and very many versions of flashers and software… The question is what! I remember flashing the stick a few years ago without any problems. ---
**Author:** ![manup](https://forum.phoscon.de/user_avatar/forum.phoscon.de/manup/32/9_2.png) [@manup](https://forum.phoscon.de/u/manup)\ **Post date:** [July 3, 2025, 11:55pm UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/6 "2025-07-03T23:55:22Z")
It’s indeed strange if this happens on two PCs and two ConBees 🤔 Can you please share a log when running the follwing command with GCFFlasher v4.9.0 from [https://github.com/dresden-elektronik/gcfflasher/releases/tag/v4.9.0](https://github.com/dresden-elektronik/gcfflasher/releases/tag/v4.9.0) ```raw GCFFlasher.exe -d -f deCONZ_ConBeeII_0x26780700.bin.GCF -x 3 ``` Another idea is to download the firmware GCF file again, we had cases in the past where the file wasn’t downloaded completely or corrupt for some reason. ---
**Author:** ![TDehli](https://forum.phoscon.de/letter_avatar_proxy/v4/letter/t/b4bc9f/32.png) [@TDehli](https://forum.phoscon.de/u/TDehli)\ **Post date:** [July 4, 2025, 11:25am UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/7 "2025-07-04T11:25:57Z")
Like this? **Windows PowerShell** **Copyright (C) Microsoft Corporation. All rights reserved.** **Install the latest PowerShell for new features and improvements! [Migrating from Windows PowerShell 5.1 to PowerShell 7 - PowerShell | Microsoft Learn](https://aka.ms/PSWindows)** **PS C:\Users\HS4\Desktop\GCFFlasher\_Win\_V4\_09\_00\> .\gcfflasher -l** **Path | Serial | Type** **------------------±------------±--------------** **COM5 | DE2462183 | ConBee II** **PS C:\Users\HS4\Desktop\GCFFlasher\_Win\_V4\_09\_00\> .\GCFFlasher.exe -d com5 -f deCONZ\_ConBeeII\_0x26780700.bin.GCF -x 3** **read file success: deCONZ\_ConBeeII\_0x26780700.bin.GCF (163244 bytes)** **flash firmware** **command reset timeout** **retry connect bootloader com5** **retry connect bootloader com5** **retry connect bootloader com5** **retry connect bootloader com5** **retry connect bootloader com5** **retry connect bootloader com5** The last line continues every half second… I also tried updating to powershell 7, without any change. ---
**Author:** ![manup](https://forum.phoscon.de/user_avatar/forum.phoscon.de/manup/32/9_2.png) [@manup](https://forum.phoscon.de/u/manup)\ **Post date:** [July 4, 2025, 3:34pm UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/8 "2025-07-04T15:34:15Z")
Hmm I don’t get it 🤔 I’ve tried also to re create the setup and flashed my ConBee II with 0x26650700 and then upgraded again to 0x26780700 here it works. **Important:** Your command uses lower case `com5`, it should be **COM5**. * * * Just to be sure that the file is not corrupt can you execute following command in Power Shell in the directory where the firmware is: `Get-FileHash -Path .\deCONZ_ConBeeII_0x26780700.bin.GCF` It should output following SHA256 hash: ```auto 5489590B5D2E108DBE4BA2A98D74995B2A5975CDA57CB9EDAF5EB82F5358059B ``` * * * Also does the current firmware on the ConBee still work with deCONZ and can connect? With GCFFlasher this can also be checked via: ```auto GCFFlasher.exe -d COM5 -c -x 3 ``` This does print some packet logs every few seconds. ---
**Author:** ![TDehli](https://forum.phoscon.de/letter_avatar_proxy/v4/letter/t/b4bc9f/32.png) [@TDehli](https://forum.phoscon.de/u/TDehli)\ **Post date:** [January 14, 2026, 9:29am UTC](https://forum.phoscon.de/t/updating-conbee-ii/6380/9 "2026-01-14T09:29:36Z")
It has been a while since I made this post, because of other non-related things I had to take care of. Sorry about that. When I came back to this problem, I downloaded all the files again, and suddenly everything worked just as it should. I don’t know what it was, but of course I must have done something wrong the first time 😉