Affected when chip lacks length (4)
I believe the answer is:
fake
'affected' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for fake that I've seen before include "Not genuine, perhaps jewellery" , "Not genuine, like forged painting" , "Counterfeit object" , "Forge(ry)" , "Phoney (like news?)" .)