There are those ancient hexipals blocking your access to the switch.
How to get past them
I have it
They like it
They look like a tribe or something. Do you have your own hexipal?
Show it to the tribe.
And they follow you (or it). Now, if you could just get them to do something together.
Like, you know, play some music in the music room. With the harp.
Have you checked the book that is at the table, in the corridor.
Right. Wiring the hexipal to those symbols would make it a harp-playing hexipal!
So, go upstairs and, by checking from the charging station, wire it until the symbols match to the ones in the book.
Here are the symbols for reference:
You have it? Good. Now, take it to play some harp music. The tribe will join and you can get to the power room.