Activating the first switch in the Institute

[Tilly Mint]

I am back in the first corridor because I need to activate the switch, I think this is the right one, before I can go up through the gates into Daryl's office.
How do I activate it? Each time I swipe at it, there is a strike of light but nothing appears to come on. As you might gather, I am spent several hours here already and just want to finish this. I haven't opened the chest, if that's any use. Any help would be appreciated. Thanks.

[Indinera]

Opening chests doesn't interfere with the switches!
^^ First switch is just behind where u meet Daryl. It's on the floor so stepping on it will do the trick. You'll notice it's down after you do so.

[Tilly Mint]

I've gone back to the second floor switch and that hadn't been turned on. So now back to the main corridor and up to the office.

[Indinera]

Good job!