SSD + RAM install - only beeps

Hello-

I have a brand new 2.8GHz 21.5" iMac that I turned on once and did a software update with. I turned it off, followed the guide on here and installed a 256GB Samsung 830 SSD. I believe I did each step completely with no surprises. The final step before turning the machine on was to swap out the OEM 8GB RAM with (also brand new) 2x 8GB Crucial DDR3L 1333.

When I push the power button I hear the HDD spin inside for ~1/2s. About 3 seconds in I hear a single beep that just repeats every ~5 seconds. If I let this continue for 5 or so beeps, the fan turns on full throttle and stay that way. Unplugging the computer and trying this again a few minutes now have the machine turning on with the fans already on full speed.

This leads me to believe it's the RAM - I tried both slots (one on top left, one on top right... one on bottom left, one on bottom right). No luck.

I tried the original 8GB of RAM. Also no luck. Again, tried both top and bottom.

Any advice would be greatly appreciated... perhaps I missed a connector?