Honeywell Home Thermostat – wiring issues?

I have the Honeywell Home – 7-Day Programmable Thermostat. When my roommate installed the device it was winter and everything appeared to work fine. Now that it’s heating up, it’s impossible to cool the apartment down. My apartment complex says the AC unit outside isn’t even kicking on. I took a look at the wiring and this is what it looked like:

G wire > G terminal
W wire > W terminal
Y wire > C terminal
R wire > R terminal
Jumper > R to Rc
C wire > unattached

At this point the thermostat still powered on. Now I have reattached the wires as follows and the thermostat doesn’t even power on:

G wire > G terminal
W wire > W terminal
Y wire > Y terminal
C wire > C terminal
R wire > R terminal
Jumper > R to Rc

Any ideas as to 1) why it isn’t powering on and 2) alternative ways to wire the device?