Okay if you live in one of these fabulous old Boston area houses you probably have an original equipment mortise lock on your front door. I had one of these on my apt in Jamaica Plain.
This was a fancy one. It had a deadbolt above and a latch below. The two buttons allow you to make the latch lock the door when closing it.
So I managed to remove it (btw “mortise” refers to the deep pocket carved into the door)
I took it over to a local locksmith and they took a look
The spring that pushes the latch outward had broken. Amazingly, Kenny’s locks in Dorchester figured it out and had it fixed within an hour.
Before putting it back in I decided I had best clean things out — oh my goodness, 100 years of dirt was hiding in there.
all fixed!