When is the shot clock reset to 14 seconds, or not reset at all?

Reset to 14 seconds (Art. 51.4):

• The same team keeps the ball with a frontcourt throw-in, and the shot clock shows 13 seconds or less, after a foul or violation (not out-of-bounds) by the opponents, or after a stoppage not connected with that team. If it shows 14 or more, it is not reset.
• The other team gets a frontcourt throw-in after a personal foul or violation (including out-of-bounds), or from a jump ball situation.
• A throw-in from the frontcourt throw-in line opposite the scorer's table after a disruptive, flagrant or disqualifying foul.
• The ball touches the ring on a missed shot, a missed last free throw or a pass (including lodging between ring and backboard) and the same team that had the ball regains control.
• In the last 2:00 of the 4th quarter or overtime, after a time-out by the team entitled to a backcourt possession, the head coach chooses a frontcourt throw-in and the shot clock showed 14 or more.

Stopped but not reset, remaining time shown (Art. 51.2), when the same team keeps the ball with a throw-in because of:

• the ball going out-of-bounds;
• an injury to one of its own players;
• a technical foul by that team;
• a jump ball situation (but not when the ball lodges on the ring);
• a double foul, or cancelled equal penalties.

Switch it off (Art. 51.5) after the ball becomes dead and the game clock is stopped, when there is a new control of the ball for either team and less than 14 seconds remain on the game clock.

The shot clock signal does not stop the game clock or the game, and does not make the ball dead, unless a team is in control.