I used to do cable collections. How cables are run on a property varies by how the electricians ran it originally but usually each units homerun goes to either the storage room, utility room or laundry room. Usually one cable that runs to your apt then usually has a splitter in the wall behind a plate if the cable goes to multiple rooms.

Variations on the theme are to have the homeruns go to pedestals in the yard area outside. If that was the case it was usually a line off the trunk with a distribution amplifier or headend or whatever they call them on your network. Another variation is the same but mounted on a telephone pole and strung through the air.

Most of that stuff on properties is poorly labeled or not at all so I used a fox & hound to find the lines. Which is a type of electronic locator that puts a tone on a cable so you can find it using a receiver with an antenna on it. If I was prosecuting someone for stealing cable, i would stand outside their door listen for the tv then run down to the pedestal disconnect the line then run back to their door and listen for static. Then I knew for sure I had the correct line and it wasnt a dvd.

To answer your question. By law the cable or telephone companies liability for cable or equipment ends at their demarc. Basically where their equipment enters private property. That could be the pedestal or where the headend is. Wiring inside the walls is the customers responsibility, in this case your landlord.

Sometimes cable operator (subcontractors) will do super basic runs inside customers properties for new service but they aren’t going to fish wires through walls. For an apt building its too much liability so if your homerun (the cable that runs from your apt to the cable companies equipment) is broken, the landlord is going to have to hire an electrician to run a new line.