K1 How to downgrade to monochrome firmware after installing multicolor firmware

Flagship K Series Creality Flagship K1 & K1C
1

I have downloaded and installed CR4CU220812S11_ota_img_V2.3.5.34.img on my K1 printer. Now, I am unable to print due to notifications about missing filament. I have tried to change a name of monochrome firmwares to CR4CU220812S11_ota_img_V2.3.5.35.img CR4CU220812S11_ota_img_V3.3.5.34.img but at some point the upgrate returns an error.

My printer is unusable. Any solutions?

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3

I hope this helps

4

No, It doesn’t. I have tried to install previous versions of the firmware. Each time I’ve got a message “…. installation failure”. I tried as well a name change, to increment it’s sem version number, to trigger an install process, but without success. Exampel: CR4CU220812S11_ota_img_V2.3.5.34 → CR4CU220812S11_ota_img_V2.3.5.35
CR4CU220812S11_ota_img_V1.2.9.12 → CR4CU220812S11_ota_img_V2.3.5.35

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5

Dang ok. Let me check somewhere else

6

Were you able to downgrade? I’m having the same problem.

7

24 hours trying to find a way to force a downgrade.

[Tutorial] How to Force Downgrade Creality K1 / K1 Max via SSH

If you updated your K1/K1 Max and can’t downgrade because the printer says “version is new” or fails via UI, follow these steps to bypass the security check.

Prerequisites:

  • FAT32 USB drive with the desired firmware .img file.

  • SSH access enabled.

Step-by-Step:

  1. Clear modifications and enable Write access:

    Bash

    rm -rf /overlay/upper/*
mount -o remount,rw /

  2. Create a “hacked” update script: (We copy the original to a temp folder and bypass the version check exit)

    Bash

    cp /etc/ota_bin/local_ota_update.sh /tmp/local_ota_update_forced.sh
sed -i 's/exit 1/echo "Ignoring lock..."/g' /tmp/local_ota_update_forced.sh
chmod +x /tmp/local_ota_update_forced.sh

  3. Run the forced downgrade: (Make sure the .img filename matches the one on your USB drive)

    Bash

    /tmp/local_ota_update_forced.sh /tmp/udisk/sda1/YOUR_FILE_NAME_HERE.img

  4. Wait: Once you see ota: stoped success, the printer will reboot into the downgraded firmware.

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