Answer: Based on your description I am not certain what has happened to your tree. Since there are leaves coming out it is not dead, but it doesn't sound good.
If this is a Japanese maple, it is possible that oscillating temperatures or a spring frost or cold snap damaged the buds just as the tree was beginning to leaf out. It is also possible that the weird winter weather damaged some of the buds, and it has been very dry, that may have caused some damage.
In my experience, you may find that some of the branch tips are dead but the tree may be able to releaf if you are patient. Once that seems to have occurred, you can trim off any dead branches and twigs. Dead wood will be brittle and off color with no green inside the bark. Begin at the tips of the branches and gradually work your way into the tree. Then trim as needed to restore a somewhat symmetrical look. Cut just outside a branch that is alive to avoid leaving stubs. Japanese maples take pruning fairly well so this would not be a permanent setback although it may affect the overall shape of the tree.
In the meantime, top dress with compost over the root area and maintain a layer of organic mulch two to three inches deep over the root zone year round. (It should not touch the trunk.) Also water as needed to keep the soil evenly moist like a wrung out sponge any time it is not frozen -- these trees are very sensitive to drought. To know if you need to water, dig into the soil below the mulch with your finger. If it is still damp, do not water yet. When you do water, water thoroughly but slowly so it soaks in deep. After watering, wait a few hours and dig down to see how fat the water went. It can be surprising. With this tree, you are looking for about 8 inches of dampness.
I hope this helps, good luck with your tree.
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