Set your first portal on the wall panel by the Light Bridge and then place the exit portal about halfway up the right-hand side of the wall panels on the left (over the pit). Press the red button and this’ll release a Cube that’ll bounce off of your suspended Light Bridge.
The problem is that the physics can sometimes mean that it can take several goes to get the Cube to land on the upper level (as you’ll see for yourself if you watch our solution video below).
Once you finally manage to snag a Cube, fire the Light Bridge portal on the upper right-hand wall (near the monitor) so it creates a barricade in front of the monitor. Now pick up the Cube and walk over the jump plate to get carried up to the upper level.
Turn to face the pit of turrets below and position the Light Bridge portal so it’s blocking the aim of all four turrets. Now pick the Cube back up and drop down to the ground floor where the switch resides. Set the Cube on the switch and immediately back away into the left-hand corner.
Welcome back to Aperture Science, a world where your Companion Cube isn't you're only company. Take control of Chell once again in Valve's sequel which takes you on an humorous and puzzling adventure and in our detail-packed guide we'll show you:
How to solve every test chamber first time.
Conquer every co-op chamber with a friend.
Loads of High Definition screenshots and videos showing you the solutions to every single chamber.
High Definition strategy videos for every achievement in the game.
Uncover all of the hidden secrets and Easter eggs.