QUESTION I don't understand

[remolab]

I everybody,
First of all this is a newbie question but I made dozen or hundreads of sites in my life.
I can't change the favicon.
I made a site with newclear theme, first thing a made I removed existing favicons code and put a code like this: <link href="<?php get_theme_url(); ?>/fav.png" rel="icon" type="image/png" /> (I have fav.png in my root).
Nothing happens. favicon dosen't appear.
So I tried to restore original code wich is the following:
<link rel="shortcut icon" href="<?php get_theme_url(); ?>/images/favicon.ico">
<link rel="apple-touch-icon" href="<?php get_theme_url(); ?>/images/apple-touch-icon.png">
<link rel="apple-touch-icon" sizes="72x72" href="<?php get_theme_url(); ?>/images/apple-touch-icon-72x72.png">
<link rel="apple-touch-icon" sizes="114x114" href="<?php get_theme_url(); ?>/images/apple-touch-icon-114x114.png">

and I modified the images but it shows the original ones (black with an s) wich I really don't know where does the theme get them, I personally changed them, the folder is clearly defined (exemple /images/apple-touch-icon-114x114.png). so what it's gonna happen?
I cleared the cache of my browser many times but it's still the same, does anybody knows what should I do?
I don't know if is it allowed to post the link of my site, if it is possible and it can help I post it.
thank you