Robin
the technician i consulted recommend me to send the motherboard alone to their service headquarters for inspecting in detail
Often it’s some dried/died Elkos on the board waiting for replacement simply, and some thermal paste between heat sinks and semiconductors. That could be diagnosed and fixed in a repair café easily, so you should check out whether there are some in your neighbourhood; there you’ll find volunteer willing to help you with this.
Windows is like a submarine. Open a window and serious problems will start.