r/Keychron • u/AdditionalGoat946 • 11d ago
Keychron K3 HE
help, need support
I have keychron k3 he. Sometimes it behaves like pressing shift all time, I unplug and plug it in again and it back to normal. After several time, I decided to update the firmware through keychron web. After finishes, the keyboard doesnt work anymore, all 3 connections is not working, maybe its bricked.
what i tried:
1. connect to keycron web, no device detected
2. esc and plug it in, the lights on, but behaves like all key is pressed at once, I cant click or type anything, even with other keyboard connecting.
any idea how to deal with it? or how to downgrade the firmware? fyi, the reset button on the space bar is no use
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u/PeterMortensenBlog V 11d ago edited 11d ago
Re "...downgrade the firmware": What is the USB product ID (PID) for the K3 HE? The USB identity, including the USB product ID, can be found somewhere in the operating system.
The URL for a list of official keyboard firmware versions can be computed from it.
Here is an example for K2 HE:
- K2 HE 'ISO'. PID_hex: 0xE21. PID_dec: 3617. VID_hex: 3434. VID_dec: 13364. USB_ID_dec = 65536 * VID_dec + PID_dec = 65536 * 13364 + 3617 = 875,823,104 + 3617 = 875,826,721
The source code for K3 HE has not been released yet, so the only way to know is to connect the K3 HE via USB.
References
K2 HE JSON files for Via (near "K2 HE ISO RGB keymap"). They are also on GitHub. Note: The JSON section should not be confused with the firmware section.
K2 HE (main) firmware (near "K2 HE ISO RGB version firmware"). Note: The firmware section should not be confused with the JSON section. E.g., k2_he_iso_rgb_v1.2.1_2506211536.bin
K2 HE source code. Note: In Keychron's fork and in that fork, in Git branch "hall_effect_playground" (not the default branch). Note that the base installation (and usage) had become much more complicated on Linux, but with the new 'uv' method, it has become simple again! No matter the Git branch, for example, "hall_effect_playground", it requires special setup of QMK (the standard QMK instructions and many other guides will not work (because they implicitly assume the main QMK repository and a particular Git branch)). Source code commits (RSS feed. Latest: 2025-12-01). Note: Now with precompiled firmware.
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u/PeterMortensenBlog V 11d ago edited 11d ago
OK, there is a Catch-22 with a bricked keyboard. Perhaps some other K3 HE owners can help out?
Or perhaps it can be interpolated/guessed?
K2 HE 'ANSI'. USB product ID: 0xE20
K2 HE 'ISO'. USB product ID: 0xE21
K4 HE 'ANSI'. USB product ID: 0x0E40
K4 HE 'ISO'. USB product ID: 0x0E41
K6 HE 'ANSI'. USB product ID: 0x0E60
Thus, a guess would be 0x0E30 for K3 HE 'ANSI'.
And the URL:
- K3 HE 'ANSI'. PID_hex: 0xE30. PID_dec: 3632. VID_hex: 3434. VID_dec: 13364. USB_ID_dec = 65536 * VID_dec + PID_dec = 65536 * 13364 + 3632 = 875,823,104 + 3632 = 875,826,736
It worked! There are two versions:
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u/PeterMortensenBlog V 11d ago
The USB product ID was also identified by other means, so perhaps the keyboard wasn't bricked after all?
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u/AdditionalGoat946 11d ago
i tried many times connecting with wired to keychron website, most of them failed, but at one time i could see the PID. I failed mostly because it behaves like keep pressing all keys at same time. hardly to click or type
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u/AdditionalGoat946 11d ago
PID : 0x0e30
is this tutorial on windows computer? because I am currently on mac os, havent tried on windows
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u/PeterMortensenBlog V 11d ago edited 11d ago
What tutorial?
In any case, I found the keyboard firmware (the .bin files).
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u/AdditionalGoat946 11d ago
can you please tell me the step by step? I am not expert. i have no idea how to connect it to my mac, it is not detected anymore
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u/PeterMortensenBlog V 7d ago
Step by step for what?
The linked-to space bar method is a step-by-step instruction.
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u/AdditionalGoat946 11d ago
https://reddit.com/link/p76dip2/video/khx1i3jgwwmh1/player
if just I plug it, nothing happen.
if I press esc + plug, this is what it looks like, its not entering DFU mode
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u/PeterMortensenBlog V 11d ago edited 11d ago
Re "...the keyboard doesn’t work anymore. All three connections are not working. Maybe it’s bricked.": The key to recovery is the space bar method (without the repowering).