SCREEN BLACK AFTER UPLOAD GIF

[CAIOCDK1]

My KNOMI V2 had a black screen after uploading a new GIF, I can't do anything else, not even access the webpage to connect, It also no longer appears as an option on the wifi, nothing happens, I remove the USB and insert it, and only the red light appears in board, not even the Hello message. I can only upload it through VSCODE, but it doesn't seem to have any effect, it completes the process with the SUCCESS message, but the screen remains black.

[Rami-Pastrami]

Same thing happened with me with 2 separate Knomi v2 boards

Attempting to use Flash Download Tool as discussed in the documentation for updating the firmware (even when trying to use the stock firmware from the documentation) simply results in "2-sync fail"

I have confirmed that the baud rate is identical in the Windows COM settings and the upload settings of the tool as well

[electrocally]

Edit: Please see my newer comment below for a fix to flash the stock firmware.

This also happened to my Knomi v2 yesterday.

I originally used the web UI at http://knomi.local to flash the new gif, following a review & tutorial from HobbyistNotes on YouTube. Exact same issues as described above by @CAIOCDK1 with no screen or WIFI network. I've attempted to use both the Flash Download Tool (same error code "2-sync fail" as @Rami-Pastrami) documented here, and VSCode using PlatformIO. Although it has no effect, PlatformIO's output insists that it is able to both write & confirm the hash of the new firmware.

Output snippet:

...
Wrote 2939840 bytes (1413934 compressed) at 0x00010000 in 36.2 seconds (effective 650.3 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...
================================================================================================================ [SUCCESS] Took 70.66 seconds ================================================================================================================

Environment    Status    Duration
-------------  --------  ------------
knomiv2        SUCCESS   00:01:10.661
================================================================================================================= 1 succeeded in 00:01:10.661 =================================================================================================================
 *  Terminal will be reused by tasks, press any key to close it.

[electrocally]

I have a fix!

Posted to the BigTreeTech channel of the Voron Discord & saw a few others had the same issue previously.

The firmware update documentation is for the Knomi v1, and hasn't been updated for v2.

At the start of the flashtool screen, select ESP32-S3

From this repository (cloned locally), you can flash the default firmware in the master branch. Be sure to select that in the KNOMI2/Firmware folder.

One important difference is that the knomi2_bootloader.bin needs the memory address 0x0. Select your COM port from the dropdown menu.

[Rami-Pastrami]

I have a fix!

Posted to the BigTreeTech channel of the Voron Discord & saw a few others had the same issue previously.

The firmware update documentation is for the Knomi v1, and hasn't been updated for v2.

At the start of the flashtool screen, select ESP32-S3

From this repository (cloned locally), you can flash the default firmware in the master branch. Be sure to select that in the KNOMI2/Firmware folder.

One important difference is that the knomi2_bootloader.bin needs the memory address 0x0. Select your COM port from the dropdown menu.

This works on bringing back the knomi v2 from death with the stock firmware! Thanks for the heads up!

The one thing remaining is that any firmware I compile fails again with the black screen issue. I thought maybe the gif I was using was at fault, but even when I change 1 C file with one of the original gifs, it still fails like this

EDIT: Confirmed with diffs that using the original C gif file instead of my changed one, and recompiling still causes the black screen issue. something else in the compile process may be resulting in this issue

[electrocally]

I was originally just very happy to have my Knomi working again, but I also couldn't get it to run the firmware I compiled.

I'm now leaning towards the conclusion that my board, or perhaps this newer batch of boards that we have, are faulty. The box mine arrived in says "D/C: 2024.2.24" on.

Once mine worked from my comment above, I tried the web UI updater using the same firmware.bin I'd used with the USB flashing tool -- it didn't crash or brick at the time. but when I turned my printer off and on, the toolhead (SB2209 RP2040) wouldn't start & everything smelled like solder. Seems to be short-circuit protection and the Knomi has somehow shorted out.

My Knomi no longer runs, not even in DFU mode, nor has a red light over USB, but does get extremely hot when plugged in. I'll be reaching out to BTT's customer service.

[CAIOCDK1]

I have a fix!

Posted to the BigTreeTech channel of the Voron Discord & saw a few others had the same issue previously.

The firmware update documentation is for the Knomi v1, and hasn't been updated for v2.

At the start of the flashtool screen, select ESP32-S3

From this repository (cloned locally), you can flash the default firmware in the master branch. Be sure to select that in the KNOMI2/Firmware folder.

One important difference is that the knomi2_bootloader.bin needs the memory address 0x0. Select your COM port from the dropdown menu.

This solves the problem, my Knomi came back, and I had already done this process, with just one different detail: the instruction number in the bootloader, I was using 0x1000

[mkryuchkov]

Still can't get something other than black screen with compiled firmware, even stock option (same commit as precompiled one). Any suggestions/solutions?

[mkryuchkov]

Answer which worked for me https://github.com/bigtreetech/KNOMI/issues/51#issuecomment-1887664967