We have one of these for our garage, but unfortunately last night, somehow I killed it :)

Long story short, someone told me its probably the fuse, but I cannot see where the fuse would be - Ive taken one of the covers off and couldnt see anything - the other cover is up against the wall and I wouldnt be able to see anything even if I did get the cover off.

Anyone know anything about these units ? Found an installation manual but its of no help.