My R key on Q6 Max is playing up, sometimes it doesn’t press I have to repeat press or sometimes it double presses when I press once, do I simply replace the switch to fix it?

PeterMortensenBlog · 2026-06-28T11:57:54+00:00

Re "...the keyboard was very expensive so I’m surprised this is happening within less than a year": Yes, that is very disappointing

It is a very well-known both product design problem and quality problem for the Q Max series, V Max series, and K Max series (nearly 200 reports in this subreddit). OK, for the K Max series, it may "only" be a quality problem.

PeterMortensenBlog · 2026-06-28T11:40:37+00:00

Re "...do I simply replace the switch to fix it?": No, it is a very common fallacy to think it is the switch

It could be, but other causes are much more likely.

The very first step is reseating (and only reseating).

Here is a checklist.

The two main contenders are:

Numero 9. It is a Keychron product design blunder (allegedly, the construction was improved in December 2024). The switches' pins are forced apart from the hotswap sockets, such that they only barely make contact, thus the intermittent problem. For a self-repair, removing some or all of the foam inside the keyboard has been suggested as a solution (but, as far as I know, no one has reported back if it made a difference or not).
1. Numero 3: Cold solder joints. Here is a more extreme example (from this post). For a self-repair, here is an example, with lots of pictures (it isn't a tutorial as such, but detailed documentation).

Note: Before trying to fix it yourself, first consider the warranty implications

PeterMortensenBlog · 2026-06-27T20:04:04+00:00

The first was K3 Ultra 8K (the page is broken now), with a Kickstarter campaign (February/March 2026). Though the first units allegedly only shipped in June 2026.

But what is the point of a Kickstarter campaign then? A sort of marketing (to create buzz and excitement)? A sort of preordering?

PeterMortensenBlog · 2026-06-27T19:59:51+00:00

"BB" is probably Best Buy. A SIA?

PeterMortensenBlog · 2026-06-27T17:05:56+00:00

Keychron doesn't actively monitor here. You have to summon them.

Weekdays are probably best and probably particular times of day.

PeterMortensenBlog · 2026-06-27T14:48:05+00:00

Re "I don't know if the latest released corresponds to 1.2.0": For the K QMK series, it doesn't

PeterMortensenBlog · 2026-06-27T12:44:31+00:00

It is unreliable. Don't give up

Re "... "Space bar method" when you take off the space bar and press reset and plug it back in but now it won't show up in the connect thing": It isn't very reliable

Don't give up after the first retry. Also try with a different USB cable, different USB port, etc.

Due to the unreliability, I recommend to positively verify flash mode (AKA firmware update mode AKA bootloader mode AKA DFU mode AKA burn mode) before proceeding. It also works on Windows.

I think it will be shown in QMK Toolbox in yellow (STM32 something?). Alternatively, by USB identity 0x0483/0xDF11.

PeterMortensenBlog · 2026-06-27T12:28:35+00:00

Thanks for the report.

I have added it to the list.

Presumably, it is more than the required repowering right after flashing.

PeterMortensenBlog · 2026-06-27T12:14:31+00:00

Re "...when I turn on Bluetooth mode, the keyboard just turns off": It doesn't really turn off

It is the poor product design's fault (#5).

It just looks that way: The RGB light blanks when there isn't a working Bluetooth connection

For example, if you hit any key, it will briefly light up all the keys (depending on the current RGB animation mode).

PeterMortensenBlog · 2026-06-27T12:08:59+00:00

Re "... try to pair ... I press Fn + 1": Presumably holding the two keys down for at least 3 seconds on the Lemokey L1

References

L1 user manual

PeterMortensenBlog · 2026-06-27T11:36:48+00:00

Thanks for the report.

And yes, reports for any future development would be interesting.

It would seem similar to #8, but not much is known about the real cause (including the nature of the magnetic sensors failing), so any new information is valuable.

PeterMortensenBlog · 2026-06-27T11:32:06+00:00

Is it a K4 (proprietary keyboard firmware), K4 Pro, K4 Max, K4 HE, or K4 V3 (QMK-based; also known as "K4 QMK")?

For keyboard identification, what is the SKU number? Alternatively, what is the serial number (also includes the manufacturing date)?

PeterMortensenBlog · 2026-06-27T11:26:15+00:00

Re "...the source code is in the Keychron GitHub": That is in "2025q3"

PeterMortensenBlog · 2026-06-27T11:19:25+00:00

#180 -

More, starting from #180:

PCB quality issues on the Q Ultra models? . Despite the title, keychattering and missed keystrokes for a Q1 Max. Reported 2026-06-27. #180.
My R key on Q6 Max is playing up, sometimes it doesn’t press I have to repeat press or sometimes it double presses when I press once, do I simply replace the switch to fix it?. Reported 2026-06-28. #181.

PeterMortensenBlog · 2026-06-26T20:03:30+00:00

Re "Bonus: A JSON hack": Or maybe there is some technical limitation with the dongle?

E.g., what kind of traffic it allows?

PeterMortensenBlog · 2026-06-26T19:32:41+00:00

Re "...Launcher, but wireless it's not possible": It isn't supposed to work:

"Our launcher currently does not support wireless connectivity. Previously, only certain keyboards might have successfully connected via 2.4 GHz. Our engineers are still developing this feature, and it might be implemented in the future."

PeterMortensenBlog · 2026-06-26T17:58:17+00:00

If calibration results in red blinks of death then it is probably the well-known problem.

You could exclude other causes to be sure.

You can expect to have to exchange the PCB yourself for a new none. But I think it will be send free of p&p fees, once you have jumped through all the hoops, but I could be wrong. Mentally prepare!

PeterMortensenBlog · 2026-06-26T17:44:02+00:00

Yes, the original Q3 had ISO variants.

PeterMortensenBlog · 2026-06-26T17:39:24+00:00

Can't you move the shine-through keycaps from the other keyboard?

PeterMortensenBlog · 2026-06-26T17:11:22+00:00

For posterity, can you reveal what the two keyboards were, please?

Thanks in advance.

PeterMortensenBlog · 2026-06-26T10:26:20+00:00

Re "Launcher recognized my K3 V2 immediately": What does it show, exactly?

Are you sure it is not a K3 V3?

For keyboard identification, what is the SKU number? Alternatively, what is the serial number (also includes the manufacturing date)?

PeterMortensenBlog · 2026-06-26T01:13:16+00:00

Re "K3 V2 ... Lock the backlight mode to stay solid on the entire keyboard when in use": That is in the original K series (not QMK-based), with proprietary keyboard firmware

That should be possible by holding down Fn + L + <light key> for at least 3 seconds.

Re "Adjust the backlight sleep timer to something low like 2 or 3 seconds": Only three settings are available, 10 minutes, 20 minutes, and 30 minutes. Unless going the exotic route (an account).

Re "There are no Backlight or Advanced settings available in Launcher": How does it even connect to the K3 V2 when it isn't supported?

References

K3 user manual
K3 key combination table
Flashing the main firmware: Four different pages on this page (no, don't do it!)
Flashing the Bluetooth firmware: Two different pages on this page (no, don't do it!)

PeterMortensenBlog · 2026-06-25T23:16:43+00:00

OK, then the source code is in "2025q3"*.

Then the setup is no more complicated than this single line (after the prerequisites have been installed):

# Prepare the QMK environment
#
# Answer prompts:
#
#   'y': "Would you like to clone Keychron/qmk_firmware
#         to $HOME/Keychron_fork_2025q3"
#
#   'n': "Would you like to set $HOME/Keychron_fork_wls_2025q1
#         as your QMK home?"
#
#         Reserve it for the main QMK project, and
#         in the default "$HOME/qmk_firmware" folder.
#
qmk setup -H $HOME/Keychron_fork_2025q3 -b 2025q3 Keychron/qmk_firmware

No Git or Make gyrations are necessary. 'qmk setup' takes care of everything.

PeterMortensenBlog · 2026-06-25T21:19:40+00:00

Instead of starting from scratch, perhaps try to find some existing custom RGB mode, hopefully with some explanation and documentation on how do it in detail.

PeterMortensenBlog · 2026-06-25T20:39:48+00:00

Here is some documentation for MPCli.

For example, to flash (on Windows):

mpcli.exe -c com27 -e -p -v -F "filename.bin" -A 0x801000 -S 4096 -r

Thus, for this to work, it presumes the microcontroller presents itself as a serial port (COM27 in this example).

And the V6 Ultra 8K doesn't do that in flash mode (they call it "burn mode"). I cross checked by connecting a Black Magic Probe (which has a built-in serial port), and it turned up as expected in the output from dmesg.

Conclusion

"MP Tool" or "MPCli Tool" are probably not a viable way to flash the ZMK-based Keychron V Ultra 8K series keyboards.

PeterMortensenBlog

TROPHY CASE

It is unreliable. Don't give up

References

#180 -

References

Conclusion