Contribution from bad Vlad set down (5)
I believe the answer is:
input
'contribution' is the definition.
(input means someone's contribution to something)
'from bad vlad set down' is the wordplay.
I cannot quite see how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is found in the answer.
'set' could be 'put' (synonyms) and 'put' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for input that I've seen before include "Energy" , "Resource" , "Data contributed" , "contributed information" , "Signal supplied to a device" .)