Key not working after cleaning - Repairideas needed w/o Topcasereplace

Hey there,

i just got an 2010 Polycarbonate Macbook and it was pretty %#*@ dirty, cleaned it with Isopropanol and now the L key does not respond at all. Neither with Shift/Option or any other combination. Removed the key and the little spring, found no visual liquids.

Is there a way of getting it fixed without replacing the topcase (150$ for a single key... ) ?

Cheers~