Locking knob will not engage

I know having a keyed entry in the doorknob is not really safe but just for now...I have a bigger problem. The original lock has stopped working. When you engage the lock and twist the knob the lock does work. It seems to be some type of alignment problem? The door had locked in the past but now I cannot get the lock to engage the strike plate. Is there a fairly easy fix I can do to align the door? I already bought and installed a new Brinks lock and the problem still occurs.
Any suggestion would be greatly appreciated.

 

Welcome to the forums! One of the most common causes of misalignment is the missing 3" screw in the hinges to draw the door to the jamb and attach it not only to the case, but to the underlying framing. If your door hinges have 4 screws, remove one of the screws closest to the stop and replace it with a 3" screw and tighten it fairly good. You will notice it move a little. Check the alignment and let us know how it goes.

 

If the issue is the bolt striking the plate and not entering the cavity in the frame it is definitely an alignment issue. This could be attributed to a number of things from the door dropping or sagging, humidity affecting the door or frame, new weather stripping, and on and on the list goes. The quick fix!

Get some lipstick!
Extend the bolt or latch with the door open.
Paint the end or face of the bolt or latch with the lipstick. Retract the bolt or latch and close the door.
(**NOTE** If using this method on any kind of sprung latch you MUST hold the latch in when closing the door to limit transfer of lipstick)
Now with the door closed extend the bolt or latch until it strikes the frame/strike plate.
Retract the bolt or latch and open the door.
you can now clearly see where you have to remove material for your bolt or latch to operate! Use a file on the plate or move it on the frame.
This will not correct the problem with the door if your hinges are sprung or loose allowing the door to sag or preventing it from closing, but if all other repairs have been made and alignment is the last issue it should do the trick!

 

Although I agree with your methodology, the door fit in the frame when it came from the factory, and has only recently become askew. Correct the door alignment before taking a file to anything. Filing the plate is making the bolt move, but not correcting the initial problem. Do the long screw thingy first.

 

I must be getting old, removed one screw from hinge so I could take it to the hardware store to get 3" one. When I got it out noticed how short it was 1 1/2" approx. that's when I took a 'real' look at the frame. I have panels on either side of the door with glass panes. That's why the screw is so short and why I should have realized first thing that a 3" screw is too long.
I also tried moving the plate (on the frame) towards me as much as I could using the existing screwholes, but didn't work. I can try the lipstick trick but the plate has a lip on it, could be tough trying to file that down.
I also noticed that this problem may be related to the cold. A few days ago it was fairly warm outside and the door worked for one day. It has since cooled down and has not worked again.
Am I out of my league here?

 

Well, the best thing is the longer screws to keep everything snug, but if thats not possible and the door is sagging a bit...

Try a small shim under the lower and middle hinges. Regular playing cards work pretty well. You don't normally need too much. Something like 2 cards under the bottom, 1 under the middle. Thats assuming all the existing screws are tight and the latch isn't entering the hole in the plate because of contact at the bottom of the latch.

 

Thanks, it's raining today but will try that ASAP. When I step back from the door (from the inside) it does sort of look like it's slightly tilted down on the lock side. So shimming the bottom might do the trick?
Also wanted to thank all of you for the help, 'chandler', 'The Locksmith' and 'Gunguy'. Should've said something sooner. You guys are great. Thanks.