node js file on centos running but not working

I have a .js file that is correctly working on another cent os vps, but on my vps when i run it using :

screen
node nodefile.js

I get nothing as output and when i try to use it using it's listening port (9615) i don't get anything as result, I've already installed node js following this tutorial :

https://www.digitalocean.com/community/tutorials/how-to-install-and-run-a-node-js-app-on-centos-6-4-64bit

any suggestions please ??