I have deadbolt lock for a closet. The key no longer works.

Schlage FAQs Schlage
The double cylinder deadbolts are keyed on both sides. On the interior side of the home there are drive pins (sometimes called screw covers) covering up the screws. Recommended method: Indent the center of each drive pin with a nail punch. Then use a carbon tip drill bit (about the size of a pencil lead) and ONLY go down 1/8". The drive pin will disintegrate. The drive pins will need to be replaced as they are no longer usable.

I noticed last time I changed locks if I tightened the 2door knob pieces to much I couldn't use lock at all.loosened just all and works no problem

With the door open, remove the interior trim (thumb turn) from the door, and using the key, turn the deadbolt to the locked position. Now re-install the thumb turn, in the locked position, and with the key removed see if you are able to unlock the deadbolt. I suspect that the tailpiece (part that sticks out of the lock cylinder and into the thumb turn) is not in the correct position.

I presume you figured it out by now, but if the tailpiece is installed wrong in many deadbolts, the key won't come out in one position or the other. It's called a "timing" problem and the way to fix it is to take it off the door, turn the tailpiece a half circle and put it back on the door. Usually Kwikset locks are designed so you can't put it in the wrong way, but it can happen. (If it's not the timing problem, then the deadbolt unit is defective or broken. They are designed to fail in a way that keeps them locked, so this could be a sign that someone tried to break in, or that someone used the extended bolt as a way to stop the door from closing and it hit the door frame too hard.)

The best way to install a deadbolt lock without the instructions handy is to look at the "lazy" cam and see if there is a way to install it wrong and don't install it that way. Example: If there are 2 ways for the tailpiece to fit in the deadbolt unit when the deadbolt is retracted and only one way for the tailpiece to fit in when the deadbolt is extended, then install the lock with the deadbolt extended and you can't install it wrong.

Recommend resetting the lock back to factory settings and try reprogramming. Also if you don't hold the latch while turning the key to lock/unlock the door it may not be recognizing the keys inserted and this will keep the key in place. Try that before resetting to factory just make sure you hold latch and turn key until it wont turn anymore.

The deadbolt may very free inside the deadbolt hole... This system is low torque and a over torque clutch may slip if the dead bolt it's not completely free inside the deadbolt hole... Also, if you try to open the door before to unlock it, you may block the deadbolt... take care to unlock the door before open it. to be sure that the dead lock is ok, you can turn the manual knob and be sure is turning very very easily.

Also are you no that POWERBOLT is a 3 codes memory? go to that link to see more info about that : http://www.fixya.com/support/t8006865-not_overwrite_old_codes_just_keeps

Have a good lock
Have a good unlock

Depends what side of the door you are on. If you are able to be on the inside simply remove the screws that retain the deadbolt lock, and remove it completely. If however you are on the outside of the locked door you may need a locksmith. You could try to drill the key slot out and otherwise bust the lock, or perhaps use a pair of vice grips and unscrew the lock part. This is dependant of what type of lock it is.

it sounds as though the linkage that pulls the deadbolt back has disengaged... if you undo the screws from the inside of the door and remove the manual knob there will be 2 more screws holding the key lock to the door. A thin flat bar is attached to the key lock that goes through the deadbolt and into the manual knob. This bar turns with the key, sliding the bolt on its track to lock and unlock the door. Once the lock is apart check the key in the lock to see if the bar turns when the key does. then see if there is anything that may be obstructing the deadbolt from sliding. The locks are pretty indestructible so if there is a problem it may have been from the install... perhaps the door is to wide for the lock to engage properly and the lock worked loose in the 6 months that it worked.

Sounds like the tumbling mechanism for the handle may be off......check to make sure that the screws are tight that lock the front and back of the deadbolt together. Make sure that the door is fully closed and check to see where the deadbolt is hitting the striker. It mat be as simple as the door and frame have expanded a bit and the door is not fully seated when you close the door from the inside. See if these help if not please contact me as I wish to find a solution to your problem.

Thx
Deathstalker

spray a little bit of oil where you insert the key turn it a couple of time to make sure it is lubricated then turn to correct location to pull out key hold cylinder in with finger key should pull out