I think these are two different problems, but maybe not.
I put in a pear tree two years ago that started blooming this spring. I got exactly one little pear that started to form after the flowers were gone. Then the stalk it was on turned black and the little pear (about an inch long) fell off (and a rabbit ate it!) What happened and how can I fix it next year? The pear tree itself looks healthy, but towards the end of the season last year the leaves started to curl up, even though I was giving it water every day (not enough?)
In a different part of my yard (close to the street where the snow plow comes-- they salt the roads here-- it might matter, I don't know) I planted a masabi cherry treee at the same time as the pear. The first season it bloomed like mad (and I was surprised because I thought for sure it would take a whole year) and made cherries. This spring it also bloomed (not quite as copiously) and made a few little cherries. After making the cherries, it started to leaf out and then it was like a switch got turned and everything dried up-- even the cherries (but they were the last to go). I was watering it (not enough?) It currently has exactly two little mal-formed leaves and I think it is a goner. What went wrong? I loved that tree...
Fruit trees are kinda fickle. They are very susceptible to fungus and insects. The first thing in the spring, before any buds start to break, you have to spray them with lime sulfur (a fungicide) and dormant oil (an insecticide) these will kill any overwintering insects and fungus. It is available in Canada as a dormant spray kit. I'm sure you will fin it available that way in the US. Then you have to buy a fruit tree spray that will also be an insecticide/fungicide mix. You can only use the lime sulfur and dormant oil first thin in the spring. If there is any green growth of flowers showing, it is too late as the oil coats and will damage the tree. You should spray the fruit tree spray throughout the spring and summer on pears as they don't harvest until fall. But NEVER spray any chemical while the tree is blooming as this will kill the bees that are there to pollinate. You also need two cherries (unless your neighbour has one) in order to get fruit. (unless it is a sour cherry which are self pollinating.) Same goes for pear.
OK, now to deal with the present problems. The cherry may have a fungus. Spray with the fruit tree spray or a broad spectrum fungicide. I would go to a local garden centre and ask to talk to the resident expert to reccommend a chemical. The cherry may not be dead. look at the branches. if the bark is OK, it may be fine. Every tree has 2 chances. Secondary buds will be found at every leaf node. If you flick one off and it is not going brown, then it will be ok. If the tree bark on the branches looks wrinkles, then you have a problem. If it looks like it is shrinking, drying up, then the tree is probably dying.
As for the pear, it sounds like a fungus. I would look under the leaves of the new growth, as this is where insects usually hand out and I would spray it with an insecticide/fungicide too.
Good luck and let me know what is going on. Go look at the branches close up