Exact match domain homepage not ranking for brand name

Hi,
A website I work on has dropped from the SERPS for the homepage, the site is an exact match domain which is also the brand name. There are no wanrings in webmaster tools.
Things i am doing:
Adding more static content to the homepage.
Checking the htaccess file
Gaining high authority links
Has anyone else had any similar issues, i am racking my brain to work out why just the homepage has dropped. Any solutions would be gratefully recieved.

See original post by Gman1