Blender 2.79 cycles texture bake

Hello everyone. I decided to learn baking for mutliple reasons, but all i got after few days is a headache.

This is my model:
It uses 3 materials, each one has image texture linked, in two cases it is unwraped to only small part of that image, in third case it uses texture tiling.
Desired result is to have nice normal and texture image to use it for single face at my final model.

First i baked normal. I created blank image, made new UV map, used folowing node setup: node_normal .
Result is perfect, exactly what i wanted: normal .

Then i wanted to bake texture image into same UV map. Well after folowing like 20 videos and getting no or terrible results, i will post workflow that got at least some result.

I created another blank image. At my object i used folowing node setup for every material: node_bake .
Then i duplicated object, left duplicate at same spot. Duplicate has 1 material only, and folowing nodes: node_dup .
I unwraped it, using same method like i did at normal, so UV should match it. This is how it looked before i pressed “Bake” button:

And this is result: . This is one weird result out of many, using different steps once i managed to get bake of all three materials, but terribly distorted, other times something even more weird…

I’m still total newbie to 3D modeling, so it may be i get baking total wrong, what is it used for and how… anyhow does any of you know good workflow for doing it at Blender 2.79 cycles render?
Sorry this post is so long, i wanted to describe everythign as much as possible. I can send blend file if needed, but it is incredibly messy, i don’t want to couse anybody a pain :D.

Ok, after some break i did some testing again. I tried to make completely new project, make some different object, use 3 materials with texture images. It baked without any problem, basically every method i used is very easy to use with good result. So i went to back to door project/object, double checked everything, used exactly samy workflow, and baked fail again like everytime before. Then i copied door object to new project, did nothing, baked and result is exactly what it should be. So i dunno how, and what is screwed at my old messy project, but it prevents me from texture baking. Anyway i can bake now, i’m happy, so sorry i bothered here.