the way I put the nodes, in a chronological order, node 12 is connected to the positive vcc source, node 15 is not

 

Net 15 looks like this, but these are the only connections:

 

Nu înțeleg cum aș putea conecta nodul 15 la vcc, deoarece vcc este conectat la 12... nu înțeleg asta

 

cum aș putea conecta o tensiune pozitivă la nodul 15

 

hi @andreeak
If you persist in not using English text, we will close your thread.

Moderation.

 

Ok

 

Când You help me,please @eetech00

 

LTspice always has a .asc file of the simulation circuit.
Why can't you post that file?

 

Când You help me,please @eetech00

We need to see a schematic of the circuit you are trying to build.
Post a photo of the schematic...it can be hand drawn...that's ok.