[kepikimut]

here's what i do when this happen with me.
pull it from the media, clean all the brown part. dont affraid to cut the brown rizhome.make sure to clean all the brown part.
if it still have some good rizhome(white and look fresh), give some fungicide.
then warp this rizhome with spaghnum moss&pot it. give it plenty of water in the water tray. usually i dip my pot amlost 1/2 pot.
and i put in full sunlight.