In this chapter of the Control guide you can find a description of the solution another of the puzzles in the game - hidden TVs that need to be thrown into The room with the furnace. In general, you can find six special TVs, which then need to be transferred by telekinesis Into the chamber of the Furnace and throw them into the fire. As a reward you will get the best modification for weapons in the game.
Where is Furnace Chamber?
Furnace Chamber is presented in the picture above - it is located in the south-west part of the Maintenance sector. One of the checkpoints is near that area.
The first TV you will find in the NSC Power Plant section next to the pipe, on the lower level.
The second TV is also on the NSC Power Plant site - at the top of the structure in the center of the hall. Use levitation to get to the top, and then quietly go down with the TV.
Near the entrance to NSC Power Plant you will find a small door and a pantry-in the middle of another TV.
Another TV in the Furnace Chamber - use levitation to climb up.
The fifth TV is also in the Furnace Chamber. You'll find it at the top of the closet.
The last TV can be found at the NSC Cooling Pump. It's on the fan, under the sign and near metal stairs.
If you throw the TVs in the oven (the order does not matter), you get the Eternal Fire modification. It gives a 100% chance of recovering ammo when hit - it's the perfect modification for the weapon Bracket, which gives the weapon an almost infinite ammo.