This site was a custom sharepoint site developed in sharepoint 2010. After my company did an upgrade to 2013, most of the layouts and css styles were messed up. I have managed to put the homepage back to its orginal state but now i've got stuck with this issue of missing menu images from the top ribbon. The new gear icon(site acction) is missing as well. here's a picture below of my ribbon. Thank you for your help!