FP Zero won't turn on

[luisito]

I've attached a couple pictures of the raspberry pi zero because I'm guessing that's where the problem is. I managed somehow I think to solder it a bit crooked (you can see a tiny bit of space between the header and the board on the right side?). Logic dictates that's where the problem is, but I don't know enough to be sure.

Hey there! 

If I may add my 2 cents here.

Based on the pictures that you have provided, it would seem to me that there might be a couple of problems with the quality of solder work as you have suspected. I can spot many cold solder joints, etc.

Some suggestions:

1. Make sure that your soldering tip is reaching between 360 and 390 degrees Celsius. This is my favorite range, and has worked excellent for me.
   
2. Use flux. This will make sure that the solder sticks and flows perfectly between the pin and the hole.
   
3. Depending on the condition of your solder tip, you might need to clean it and recondition it. An oxide surface will not allow the solder to melt at the proper temperature because it acts as an insulation, and also an oxide surface will not make your solder "wet", the solder will not stick to your tip, so you get really bad soldering work. Heat up your solder, and clean it using a brass wool, make sure that all the oxide gets cleaned. You might also use ultra fine sand paper if the oxide it too stubborn (but let it cook before you touch the tip), fine enough to remove it with some work, and fine enough not to damage the tip or leave marks. Then you would need to heat your tip to 250 degree Celsius and reflow your tip with solder. This creates the protective layer. Let it cool. Then crank to 360 to 390 to work. Make sure to clean as often as possible your tip while working, don't let the tip have an oxide layer. A brass wool it not the same as the kitchen steel wool, steel will destroy your tip.
   

I use a professional Hakko soldering station, so I am well experienced in cleaning, reconditioning and take care of those expensive tips.

The solder work on your board needs to be reworked. 
Even if you get a new board, don't attempt anything on it after you have gotten enough practice with the old one. 
At last resort, you can buy a board with presoldered headers or get those solderless headers that you hammer in.

Here is some useful info: Soldering Problems, Weller Guide, Digikey Guide.

Hoping this helps!

Quick edit: The crocked header is not a problem that will cause you to have connection failure. This will cause an inappropriate misalignment between the boards and the case, where other components can make the problem bigger. But not a connection failure.