Points were connectivity points found at either end of an impulse pack. Defective points on an impulse pack may results in a blown impulse deck.
In 2265, the USS Enterprise's starboard impulse pack was severely damaged due to an encounter with the galactic barrier. Gary Mitchell, who had gained incredible psychic powers due to his exposure to the barrier, informed Lieutenant Lee Kelso, from Sickbay, of the damaged points on the pack, noting that they had "about decayed to lead." After Kelso left Sickbay, Mitchell called him a "fool," because "he'd seen those points and he hadn't noticed their condition." (TOS: "Where No Man Has Gone Before")
In the first draft of the script, these components were instead described as "neutronium conductors" and "dead terminals".