As soon as you head off the ramp, Ellie will tell you to fix this giant machine.
The power cell required is to the left, surrounded by cysts.
After you bring it back, Ellie will request a circuit board.
Head up the rock ramp, but turn to the left and Kinesis this Diamond Semiconductor for $LOADSAMUNNEY$
Heading to the objective will have you greeted by Slashers.
The circuit Board is removed via Kinesis then taken as an item. Take it back to the drill to start the fun.
You'll have to hack the terminal to continue. The Pack will come after you though whilst Ellie turns around and drops the lift for you.
Once you're on the Drill, Ellie will drive into the tunnel. Slashers and Pukers will climb onto the drill and Lurkers will be shooting spines at you from the walls. Keep an eye on the ledges as Semiconductors and Medkits will be on it as well.
And don't go near the drill.
Once you're far in, Ellie will start to drill into the Government Sector.
Which propels Isaac into a wall...whew, what a short chapter.