What to do if cylindar only moves halfway?

[Akil]

I have a couple old door locks from when we moved in and changed things. One of them works well when I do my part, but the other is a combination knob and cylinder. Since it's a bit old it seems harder to turn. I can pick the lock enough to let the cylindar move about a quarter turn but then the tension bar doesn't have enough strength to turn the cylinder the rest of the way. I tried using a screwdriver but wasn't successful.

Since I'm a newbie my guess is "operator error". Just not sure what to fix.

[Raymond]

Hello Akil.
Welcome to LP101. You will soon learn that you'll get no answers or juicy details until you provide the brand of the lock and possibly a photo. It also will help all of us to know approximately where in the world you are as we can then know what kind of locks are likely to be there. So, have fun.

[AngryHatter]

1st thing that comes to mind is a spring below or entangled with the driver pin.

[Akil]

The grey tab thing (attached to the long shaft) under the number is what needs to swing back and forth. I can push it with a screwdriver, it is shown in the unlocked position. The number shown is the only marking I've found on it. The assembly came from a US residence; we changed locks when we moved in.

[Squelchtone]

can we please see the outside of the lock, the keyway and the deadbolt and knob.

some locks only unlock in one direction, perhaps try picking in the other direction.

you may consider getting some practice locks as well, new pickers who dont have all the needed knowledge under their belt can actually screw up a lock, so picking your house locks may end up in having to take them apart and fixing them or replacing them again.

[billdeserthills]

The grey tab thing (attached to the long shaft) under the number is what needs to swing back and forth. I can push it with a screwdriver, it is shown in the unlocked position. The number shown is the only marking I've found on it. The assembly came from a US residence; we changed locks when we moved in.

The knob likely needs some lubricant, very common with Kwikset knob locks.

[GWiens2001]

1st thing that comes to mind is a spring below or entangled with the driver pin.

+1

Too short a key pin and driver pin combination allowing the stack to be below the shear line when the plug is turned is what comes to my mind, based on your description.

But as billdeserthills says, a little lube may be the issue, too.

Gordon