Where are the strawberries?

[Hollander]

So I have a couple of strawberry patches in my gardens. I have no idea what type they are as they were given to me by a friend of a friend. They are mostly in their 2nd to 3rd year in the ground. The patch has grown nicely, new plants arriving on the regular, the problem is, I'm not getting any strawberries (well, I've gotten a few tiny ones this year and none last year). The plants look healthy and throw off tons of flower buds, and I can see where the berries are starting to grow, but then they fizzle out before growing much larger than a pencil eraser. Any thoughts? I've babied them more this spring, making sure they have plenty of water and gave them some worm casting water as soon as they started to bloom. I haven't done a soil test and have read that may be important for strawberries (something about too much nitrogen?). I'm always gardening but must admit, I wing it mostly. I don't usually have too much trouble with plants, but ugh... these strawberry plants. Any ideas? Thanks! Oh, I'm in US North Carolina.