Downgrading Firmware on 8K X?

If you’d the whole story here is the post:

In short I’d like to flash my 8K X to a previous/old firmware to see if that’ll bring it back to life (as it was DOA when I opened it - screens flashing constantly and only showing “snow”). After seeing that problem is rather common and the fix is to flash the firmware I did just this - no issues/errors but ever since it’s dead. One Redditor had the idea to go back to an older PiTool (I’m now running 271) and to flash an older firmware (I’ve tried 298 but can’t find any others). When the flash finishes (it sees the headset fine, PiTool does not) all says it completes but if I unplug/plug in the headset it shows the same 299 firmware, so it’s not actually downgrading.

Is downgrading even possible? I’ve seen posts saying “I think so” but nothing definitive with evidence. So, is it possible, how and am I doing something wrong? Oh, and I tried the 3rd party tool too - it won’t see the headset at all as I have to kill all the Pimax services.



Last line of defense is usually the command line tool DfuSeCommand. One has to manually set the HMD into transfer mode, install the stm_dfu_3040_64 transfer driver (that comes with it) and stop PiTool+PiService. This worked for me in cases where Dfu.exe or PiTool didn’t.
SweViver explains the procedure here: PIMAX FOR DUMMIES #1: Getting Started with Pimax 8K & 5K+, Tweaks, Hints & Firmware Update Tutorial - YouTube
But you got it now anyways :slight_smile:


Absolutely. I’ve done it (in the past, not recently), using the tool in the post above.

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In my case I couldn’t do that as at the time my headset would ONLY show up is Pitool was running. Didn’t matter what else I’d do it just wouldn’t register it to be able to install the firmware. I can’t recall what the error on the CLI was but it was something to that effect.

Regardless I finally worked it all out by installing the oldest version of Pitool I could find, that would then flash the oldest firmware I could find and that got me back online. After that I upgraded and flashed to the latest and this time I’m all good.


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Sounds good :slight_smile:
Regarding the command line tool - I guess either the transfer driver wasn’t installed, some part of PiService still running or the HMD not in transfer mode (how to do this is shown in the video). Or some kind of USB problem (e.g. that the USB port on the case is internally part of a usb hub that the 8kx doesn’t like - but then I wonder why PiTool worked). Anyway, good it worked out!

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Agree that it’s hard to say - at that point the headset displays wouldn’t power on at all, all that would work was the USB audio device. Tried installing the driver twice, actually in both Win 10 and Win 11 (I’m dual booting right now). Regardless using the oldest Pitool and firmware I could find I finally flashed that on it, it started working so I went from there.

Thanks for the input, appreciated.


Yes sir, you’re allow to downgrade the Pitool/FW version.

In any case, because no further faults have shown, we believe it was caused by a software problem. We recommend that you submit a service ticket to our technician so that they may examine your headset and determine which Pitool/FW version is suitable for you.

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FYI - I bricked my 8Kx when I quickly closed the auto-firmware update that takes place when the latest version of PiTools is loaded after first install.
To figure out how to fix it, I found a beefed up version of Dfu.exe for download from Pimax online. It forces a firmware update to a MUCH older version and once done, you can flash to any preferred firmware version you want, as long as you use the correct version of PiTools to avoid it auto-updating.
At the same time, this fixed the crazy screen flashing that started on the latest firmware, so I’m all up to date and everything is now working perfectly again.

Just wanted to toss that info out there so people are aware. Glad you got yours worked out!

@PimaxQuorra - I can probably find that advanced Dfu.exe package again to link for people, but I figued you would know what I am talking about. This would make for a great separate thread to make it more easily searchable. Id even keep it pinned. There were so many people with the flashing screen issue after the latest FW update, that this tool should be made widely available.
Thanks my friend and keep up the great work. Still love my Pimax, and I truly love the companies attentive interaction with its customer base to continue to innovate! :slight_smile:

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