Few months ago Google's blogspot or blogger have disabled custom favicons.
So most blog masters lost their favicons that previously enabled. Many blog owners have seen the classical blog icon again.
However there is a hack or a trick to enable custom favicons in blogspot blogs.
You have to move the url of the favicon between the Style (CSS) part and closing head tag.
Here is how to do it.
Login to dash board --> Layout --> Edit Html.
Now search for the code : ]]></b:skin>
then place the url to the blogger favicon right after the above code.
Here is how it should see after you finalize it.
<link href='http://path to icon' rel='shortcut icon'/>
<link href='http://path to icon' rel='icon'/>
If you successfully done this, you should seen the blogger favicon in browser address bar.