Motherboard question

I’m new on this forum and need some help with a motherboard I’ve just bought for my GX520. Could someone identify this board for me and say what computer this is off?? I’ve bought it so I have more ram but also have the ability for more hard drives and pci cards. It was supposed to be from a GX520 I’ve fitted it to my case inserted the cpu fan and everything else that was on the original. When I plug the power lead into the psu the cpu fan just goes mental, I cannot turn the pc off with the front switch as it seems to do nothing at all. 
I really need to know so I can possibly send it back due to it being miss sold as my motherboard. 
cheers in advance

ian