Problem with RF circuit using HT12D and HT12E
I see you do not have jumpers to join each side of the power rails.  Note there is a gap on both sides down the middle for the Blue and Red outer rails.

Remember I said check power?  That means you need an inexpensive multimeter to do this.

Best practice of using the breadboard is to use short solid wire leads and neatly connect flush to the board without large inductive loops. Keep IC's close toegether and imagine that it is a printed circtuit board layout. Add decoupling caps close to the IC.
Avoid long jumper wires at all costs.



For fun here is a free tool to help design, layout and simulate.
http://fritzing.org

I've never tried this before but looks ok.. Use staples for power and ground rails.  Don't use wire with thick insulation. Try to get thin solid wire 24 AWG I believe. and lay down flat.