@Stanislav - what exactly is your 2nd video showing? Did you fix it by re-inserting the cables? Or by moving the ferrite ring which you've pointed out in the video description?

@Michel
I thought that the ribbon cable went, The reason was in the ferrite ring!
The position of the ribbon cable and adjacent cables in the ferrite ring greatly affects.
Turned the ferrite ring at 5-10 degrees.

@Bad Mister
Authorized Service Center - It is very far and long for me!
Now everything works great!

If the keyboard drops or takes a hard fall, or gets bumped around a lot, Internal cable connections inside can work their way loose. Sorry you live so far from an authorized service center... glad you are self-sufficient enough to fix this yourself.

I’ll tell you what they would have told you, although very solidly built, it is not built to “bounce”.
Tighten all connectors, and re-tighten all the screws as they can loosen over time... treat it as if it is an egg. The screen connection can work it’s way loose during intense handling. Glad you were able to fix it.

For others, if you are not adept at your own repairs, take it to an authorized service center.