Fans wont power on!

[obe1kanobi]

I have just had a new graphics card and PSU installed. Everything works fine, however the fans wont power on! I have checked the connection of the cables and they are all connected correctly. What could be causing them to not power on?

 

[Supahos]

The fans only run when needed fire up a game and they'll come on

 

[Dark Lord of Tech]

Some power supplies and graphic cards have fans that don't turn on until a certain thermal level has been exceeded.