hello i have question if i replace the logic board on iphone 5S will it effect anything ? i heared replacing logic board makes your phone work like a charm.but the touch id wont work is that true

The iPhone does not have user serviceable parts.

Unless you are an expert at small electronics repair, the likelihood that you will do irreparable damage to your phone is quite high. Once you attempt anything that involves opening the iPhone, you won't be eligible for warranty services or even an out-of-warranty replacement unit from Apple.

Object lesson:

Iphone works but is not charging after installing new battery

Why do you think you need to replace it?

saadix69 wrote:

If i replace my iphone 5s with a fresh logic board will touch id still work ?

There is no place to get a "fresh" logic board. Apple does not sell spare parts. So the only logic boards you can get were scavenged from other phones; either broken phones or stolen phones. And if it's from a stolen phone the logic board is probably still activation locked to the previous owner, and will be useless. Plus all of the other issues already mentioned.

The touch ID sensor used permanently tired to the A7 chip it was paired with. Give to swap logic boards and attempted to use your original sensor the touch ID will never work again.