whats wrong with my japenese red leafed maple?
 

Hi i am new to this,2 years ago i bought a japenese maple last year it flourished,this year it looks like it might be dead at the top, the leaves have budded at the bottom of the plant but the top and middle half there are no leaves at all . On close inspection this morning i noticed that the trunk of the plant has split where the branches seperate,it looks like there are some buds on the top of the plant but the wood doesnt look to healthy to me it has a mixture of black and dead wood which i have broken off could someone please tell me if my beautiful tree has gone to garden heaven or will a little pruning or trunk repair bring it back to it's glory. Thanks