Trouble solved by changing your locks? (3,4,3)
I believe the answer is:
bad hair day
'trouble solved by changing your' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'locks?' is the wordplay.
I cannot quite understand how this works, but
'locks?' could be 'hair' (locks can mean hair) and 'hair' is found within the answer.
The remaining letters 'badday' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for bad hair day that I've seen before include "When one's crowning glory is less than glorious?" , "When everything goes wrong (with one's locks?)" , "Having dodgy locks" , "Time when things go wrong" , "When everything makes one irritable?" .)