A successful period after court malfunction (3,2)
I believe the answer is:
act up
'malfunction' is the definition.
(I've seen this before)
'a successful period after court' is the wordplay.
'successful period' becomes 'up' (I can't explain this - if you can you should believe this answer much more).
'after' is a charade indicator (letters next to each other).
'court' becomes 'ct' (abbreviation used in road names).
'up' after 'ct' is 'ctup'.
'a'+'ctup'='ACT UP'
Can you help me to learn more?
(Other definitions for act up that I've seen before include "Behave badly (colloq.)" , "Misbehave - carry on" , "Become unpleasant" , "Mess about" , "Informally, behave badly or cause trouble" .)