Has difficulty firing when detecting and solving problems (15)
I believe the answer is:
troubleshooting
'solving problems' is the definition.
The definition suggests a present participle verb which matches the answer.
'has difficulty firing when detecting' is the wordplay.
I cannot really see how this works, but
'difficulty' could be 'trouble' (trouble can mean a difficult situation) and 'trouble' is located in the answer.
'firing' could be 'shooting' (shooting is a kind of firing) and 'shooting' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'and' is the link.
Can you help me to learn more?
(Other definitions for troubleshooting that I've seen before include "Trying to eliminate errors" , "sorting out problem" , "Problem solving" , "Sorting out business" , "Tracing and correcting faults" .)