Where is the mistake

[Hammerhead]

Where is the mistake Although I do not understand something in the electronics built this detector, but it does not work I want to know, please What is wrong

[Polymer]

Please take photos with proper lighting, for example outside - you have enough sunlight I think. At least the photos will be sharper.

From what I can see you have cold/dry soldering joints and possibly a few short circuits.

Did you clean the copper tracks making them nice and shiny before soldering?