My Z10 wouldnt come up

i bought my Z10 last year. earlier this year it fell and i had to fix the screen. After fixing the screen it was alright. last month it stopped booting, the redlight comes up and it start loading. when it get to 5% it goes blank. what coukd possiby be wrong.

Try reloading the OS, could be any number of things really. The fact you dropped it, a crappy app installed preventing a full boot, corrupt OS files. A refresh of the OS will help rule some of that out.