This TV is found about mid-way through chapter 2. After leaving the lobby area of the train station, follow the trail of developer fluid down several flights of stairs into a pitch black area that is only lit by your flashlight. When you reach the bottom and go through the door, the path will come to a T. To the left is where the fluid continues until it reaches an elevator button. To the right is a door that must be broken down via fire axe. The TV is behind this door, however you won't have an axe yet.
Go ahead to the elevator and do the forensics on the elevator button then continue on further. While traveling this way you will see 2 more breakable doors, this is the room you must progress to in order to advance through the level, therefore you need the axe anyway. Once you reach the end of this area, some shutters will go up and some enemies attack. After killing them, the axe is on the wall to the left just outside the shutters.
Head back the way you came. Be careful because there is an enemy that will have spawned carrying an axe as well, which causes massive damage. Go ahead and break into the room you are required to, as it will allow you to create a shortcut. Go ahead and flip the switch on the power box as well so you don't have to come back. The lights will come on and the elevator will activate it, but ignore it for now. Go ahead back down to where that first breakable door was and break it down. The TV will be right there.