Fixed part of mechanism wound up (6)

I believe the answer is:

mended

'fixed' is the definition.
('mend' can be a synonym of 'fix')

'part of mechanism wound up' is the wordplay.
'part of' suggests taking the first letters (I've seen 'part' mean this).
'wound up' becomes 'ended' (how things 'wind up' is how they end).
The first letter of 'mechanism' is 'm'.
'm'+'ended'='MENDED'

(Another definition for mended that I've seen is " Repaired, fixed".)

Want a hint initially instead of a full solution? Install my app