Power's not working - catching cold (7)
I believe the answer is:
faculty
'power's' is the definition.
(faculty is a kind of power)
'not working catching cold' is the wordplay.
'not working' becomes 'faulty' (I've seen this before).
'catching' indicates putting letters inside.
'cold' becomes 'c' (eg on taps).
'faulty' going around 'c' is 'FACULTY'.
(Other definitions for faculty that I've seen before include "Memory possibly" , "Part of university" , "Aptitude, talent" , "part of academic institution" , "mental awareness" .)