DELL Inspiron 7775 (Built-in Self-Test BIST) after display replacement

Hello guys,

i am using a DELL Inspiron 7775 AIO Computer. 

Unfortunately my display broke (at least only in one corner) and I got an identical display via Aliexpress (see pictures below).

Now comes the crazy...
I have replaced the display and when I turn on the computer, the computer shows me only the colors white, red, green and blue - and that in continuous loop (i think its the Built-in Self-Test). I cant boot anything.

See in Video here:

https://drive.google.com/file/d/1Mjz2q4WdVgXM8IasSXaik1PJhZBwW785/view?usp=drivesdk

To rule out a problem with the connections or the display cable, I put the old display back in and it works without any problems. I have done it 4-5 Times with the same result.

What I did:

- Updated the BIOS to the latest version.
- installed all new drivers available from DELL for this model

I just don't know what to do anymore.
The display I received is the same display, an LM270WR3 SSA1 from LG.

Display from Aliexpress:

Display from Dell Factory:

Does anyone have any idea how I can get the new display to work? Does the BIOS not recognize the new display? How can i exit this color changing loop?

Best regards