|That model didn't come from IBM with a TV tuner card but you might have one that was added in by someone.|
Look on the back of the tower down in the add in card area for a card with a coaxial connector on it. That is the type of connector that is on VCRs and DVD players that connect to TVs.
To get a better idea of what you do have I suggest you download SIW.exe and run it.
Get it at the link below.
If you have a TV Tuner card you will need software to use it properly.