esmi on "Toggle Image Linking back to old website on hover"

I've recycled an old theme, which I'm using 0% off, was just a starting point for a new rebuild.
However on my toggle, when you click on it, it's src is pointing back to the old website and not mine.

I've ran a changedb.php on the database however there is no trace of the old domain within the database.

I've checked how the toggle is being called in the header and footer and it's just this:

<img src="<?php bloginfo( 'template_directory' ); ?>/images/device-icon.png" alt="close" />

Not sure as to why it's still going back to the old website. You can tell as the hover state on the toggle shows an ugly green background which I never wanted!

Any help would be much appreciated!

My website is: http://sadiemangan.co.uk/dev

I've even run this SQL via the SQL on PhpMyAdmin:

UPDATE wp_posts SET post_content=(REPLACE (post_content, '<old url>','<new url>'));

with the correct URLS of course and nothing has been changed, 0 tables.

So it can't be the database?