Xbox 360 oblivion, thieves guild, big heist, old way?

I am on the last big heist for the theives guild and cannot get past this one part to complete the mission. I am in the old way at the part where theres a gate and two buttons. It's elvish-looking. I have pressed the buttons in so many different ways but always end up getting shocked and the gate is never open. Please help! This is very frustrating! I need it step by step. I just hope it's not a glitch.