Using your eyeballs and a flashlight look inside the lighter socket.

See those two metal tabs that don't touch anything?

Use a PLASTIC item like an old toothbrush or broken Plastic fork handle and gently tweak those two tabs back to the center of the socket. If you use metal you will pop a fuse. Slow and steady pace wins the race. Gently bend, test the lighter. Rinse repeat. Both tabs should touch the lighter the same! When the lighter glows red for about "one Mississippi two Mississippi" you have it fixed. Don't bend too much at once.

You'll know you got it when you press it in and it feels like it used to. Just don't try to bend a lot all at once. The tabs grab AROUND the stainless ring that encompasses the spiral lighter element. They expand when the element gets hot and it releases the lighter. Proper function is glowing red but not brightly. Too bright and your lighter will fail prematurely.

Good luck and use kid gloves! (Gentle hands)