Speak to Fai Dan a second time, after fighting off the geth which interrupted your first conversation. He will tell Shepard about the transmitter. Alternatively, entering the tunnels and destroying the transmitter will begin the assignment.
The transmitter is guarded by a small group of geth in the tunnels. Head towards the elevator to the skyway, and continue down the stairs beyond it. Once in the tunnels several geth will need to be fought to reach the room containing the transmitter. This room can be found through a door across a small bridge.
After the door opens, Shepard is fired upon. There are Geth Snipers waiting in the first area, on a ledge above the main level, and a Geth Assault Drone lying in wait. After dealing with these geth, three Krogan Warriors will attack from the main chamber. Once all of these enemies have been killed, proceed to the back of the area to find the transmitter. Shoot the area indicated to destroy it. Don't use grenades or explosive/incendiary ammunition to destroy it, this may cause a glitch and the assignment will not be possible to complete. Once the transmitter is destroyed, return to Fai Dan to receive the reward.
- Warning: If you clear the tunnels of geth and don't speak with Fai Dan before he commits suicide, this assignment can't be completed.
- Warning: Make sure you shoot the transmitter instead of destroying it with grenades or high explosive/incendiary rounds. Destroying it with grenades or explosive ammo will make the transmitter disappear as it is supposed to, but may cause a glitch where you will not be able claim you reward from Fai Dan and the assignment will permanently appear as not completed in your journal.