M15x Fans won't spin

Hi All

I really hope someone can help me - I have a problem with my M15x where the fans just won't spin up to cool the laptop down.  If I try and play a game it lumps and lags like nobodies business.  If I get the fans going then everything is great.  It's starting to get on my nerves because I can't readily fix it.  Rebooting several times seems to get it going again but its very hit and miss.

I have updated every driver and the BIOS to the latest available and nothing has helped.  Does anyone have any ideas or is my laptop broken and do I need to send it back to Dell?

Best Regards

Back4Breakfast