I like the idea of LDRs for tracking the sun. It is wonderfully simple.
@alehandro, you have posted links that (presumably) show how your project should be connected, and perhaps / probably how it was connected. You have also posted a link to code that is, I assume, completely unchanged from the code that worked before.
With that information I have no means to give you any advice about why your project is not working now.
If the code is unchanged it seems likely that the wiring now is different from what it was. Of course some part might have become damaged but I have no way of knowing that.
The best I can think of is for you to draw a clear diagram of how it is actually wired now and post a photo of that. Keep the photo to 640x480 if possible.
It is also probably a good idea to write a few short sketches to test each of the pieces of your hardware on its own.
...R