DID YOU INSTALL PC3L (DDR3L) RAM? Haswell and Broadwell both require 1.35V RAM and cannot officially accept 1.5V RAM, as it can damage the memory controller (integrated into the CPU). Dell specifically blocks DDR3L machines from continuing POST VERY EARLY if 1.5V RAM is installed for this exact reason. In addition to that, some of the "DDR3L only" Dell motherboards are picky about mixed RAM and only like it one way, or not at all with that mixed pair.

If you purchased the wrong type (PC3=1.5V/PC3L=1.35V), then the motherboard is shutting down as a protection measure - this happens before anything else for a reason. If it is PC3L, there may be a board or CMOS RAM issue. Pull the CMOS battery and see if it works; if not, try another set of RAM. If neither of those fix it, bad board. Refer to this page for more information.