Virtual Host on Nginx Ubuntu

Hello, I am using Ubuntu installed Nginx & all needy thing to serve website… I am beginner first time using nginx web server software. my server block for every domain is…

    server_name my_domain.com www.my_domain.com;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    error_page 404 /404.html;
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /var/www/my_domain.com/public_html;
    }
location ~ \.php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass unix:/var/run/php5-fpm.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include fastcgi_params;
    }

location ~ /\.ht {
 }
}

after this

sudo ln -s /etc/nginx/sites-available/my_domain.com /etc/nginx/sites-enabled/my_domain.com
sudo service nginx restart

My website dont work properly…

One my wordpress site homepage are working fine but any sub-pages means post or pages are not open… & my 2nd wordpress site are working all fine… One my php site post, pages or anything - when open showing only its homepage

Please anyone suggest What I missing to work proper Your help would be appreciated Thanks