Video here: https://youtu.be/XdeITBGOcxc
As seen on the second video voltage U4 e -3V, not 1.6V - definitely U2B e is bad. I ordered several pieces of aliexpress - I will replace it myself.
Video here: https://youtu.be/AVbDQ3Q0pu8
The problem for me is U5 - I need a programmed chip. I hope we can sort out the problem.
I exchanged messages with the seller - can not help me. I suggest that I repair it myself and he would restore my cost



Greetings,
P.S. I apologize for my bad English