Gradient Map Tool not working for me

[Chris_04]

Hello,



I am a bit frustrated as I cannot get the gradient tool to work on my photos. Something is not right.

I work with Photoshop CS6.


1. The photo is open (png-format).

2. I create a new layer.

3. I try to apply the gradient tool, but nothing changes in the photo.
 
4. When I click on channels, I see that the layer mask is not marked as visible but when I mark it, the gradient map appears but is red instead of dark.


Maybe someone can help on what I am doing wrong?

Would hugely appreciate any help.