Will not recognize External Drive

[MacOCD]

I just turned on my iMac, and it will not connect to my external drive. It was working a couple of hours ago, and now they won't show up. Any help? And yes, i checked if it was connected ._.

 

[BlueRevolution]

Is it on? Sorry, had to check.

What is it formatted as?

 

[r.j.s]

Does anything show up in Disk Utility?