This might sound a little complicated but here goes... Remove blown fuse and replace with new fuse #21. Hope that helps
*add-on* If your still blowing fuses you might want to check to see if too much current is passing to the head unit/system components. Im no auto electrician, but if you do have too much current passing through that particular fuse, you might want to change your source of power (maybe directly to the battery if possible). Good luck.