You left out a lot of information for someone to troubleshoot.
1 what kind of freon?
2 What changes have you made before it would not cool?
3 what are the cfm coming from the blower?
4 what are the pressure readings?high and low?
5 Did you change out parts? did you install the right ones?
6 what is the tons?
7 what is the superheat?and subcooling?
don't be fooled by contaminants in a system they will give you different readings,which might seem good
but are really not.
I have found 410a in a r22 system before and that will make you pull your hair out.
if you have more than one system doing this check your freon.
if a system calls for r22 put it in,never mind hotshot or some other sub,I really found out it is better to use the same freon that is called for.
do you know how to check you freon to make sure it is okay?
just remember that pressure = temp and you know if it's contaminant free.