Tried klipper update - "mcu unable to connect"

i bought the official klipper touchscreen update kit for my SV06, installed all the cables and stuff, and got this. i’ve tried rebooting. anyone else experienced this?

Ive got this trouble aswell anyone got a fix for this please thanks colin

Get another cable. Had this problem. Used another problem and everything worked as it should.
Good Luck!

Same happened to me. It occurred when I updated klipper from within the klipper app — Would seem reasonable, right? Apparently, you can only update it using the Sovol update for their Klipper.
Here’s the, sigh, extensive resolution offered by Support:

This error occurs because you “updated” my klipper software through the Klipper wireless connection. As mentioned in the previous email, updating the software will cause the image file to be damaged. If a black screen (error report) occurs during the update, the user needs to do it himself. To purchase the MKS EMMC Adapter V1.0 programmer, you can purchase it on AliExpress

Re-flash the original SV07 image file for repair.

  1. Use MKS EMMC Adapter V1.0 burner and balenaEtcher software to refresh the screen image file.
    Image file + balenaEtcher software + refresh file tutorial video, please refer to the link: How to Flash SV07/SV07PLUS EMMC Module - Google Drive

  2. After flashing the image file, you need to flash the SV06plus screen firmware again:

https://drive.google.com/drive/folders/1vpKWQXOMGV58dYcx2wK9wJC0HJNqU8tg

So I hope you fixed the problem by now. I encountered it just now and what fixed it for me was checking if all the cables are properly attached, namely the one for the actual printing unit!