Front fan replacement no longer functioning

My front fan replacement, 

is no longer working after removing stock cpu cooler to replace it with this - 

which I could not screw in, because the brackets have no hex bolts, they just have circles, which cannot be gripped. After placing the stock back on, and plugging back in the gpu power and putting the gpu back in, which I had removed, the front fan did not start. I had not unplugged the front power cord. My only guess is that it may be smashed behind the GPU, which is double-wide, why I removed the 28 mm fan in the first place for a 20mm. The 20mm worked until I did this.