Broken hinges are a common problem with euro-hinges, and less common with old exposed hinges or knife hinges.
What do you do when a cabinet hinge breaks?
First, take the hinge off and record all of the names and numbers stamped thereon. Take some digital photos of the hinge from all angles.
Next, look to see who manufactured the cabinets.
If the cabinets were made by a manufacturer, rather than a local cabinetmaker) there should be a stamp or sticker on a drawer box.
If you find one, contact the manufacturer, if they are still in existence.
Google the name to find them.
Such hinges are usually lifetime guaranteed, so the manufacturer should provide them free of charge. They may want to see a picture to ascertain that the cabinets are theirs, if you do not have piurchase records.
Even if your cabinets were locally made you might have some recourse, although you will probably have to buy the replacement hinges once you find them.
Most cabinet dealers save old hinges and drawer slides. I did when I was a cabinet dealer.
So your next resource would be any local cabinet dealer...especially those who have been in business a long time.
Call and ask them if they have a supply of old hinges and, if they say they do, and they have yours, ask if you can buy a few.
The reason I say buy a few is that, if you have broken one, others will follow in the coming years.
Euro hinges that mount on face frames are commonly broken because they open only to 105-110 degrees.
It's very easy to stress them by opening them to the end of their swing (as in the picture at left).
Cabinet dealers learned this early on and collected them to satisfy calls from past customers.
The third option is a big city hardware store. Some older ones, like Hundley Hardware in San Francisco, stash old hinges. Don't expect to find them on a web site. You will have to call or email. Email your images.
The fourth option is a recycle yard that sells old cabinets. They will often also have boxes and drawers, full of old hinges. One that comes to mind is
Urban Ore in Berkeley, CA. It may even pay you to buy an old cabinet just to get the hinges.
I always order a few extra hinges for my clients nowadays, especially if they are euro-hinges that do not open fully. That way they have them for just this sort of problem.