According to the walkthrough, the three yellow disks are already lit, so:
There are four controllers around the periphery of the room. Go to the upper left controller. It's dull gray and sitting at about 10 o'clock. Click on the floating circle to shut it off. The yellow disks in the center go dark. You must do this first to clear all the circuitry.
If you go to Mixed Bag, more birthday wishes await you.