I had a similar problem with one of my Dw. Cavendish a few weeks ago. It lasted for about two months. It had been bitten by the cold (not quite frost), at least I presume. I could see down into the corm that the top of the new leaves and one that hadn't fully emerged, were all brown and dried up going down into the corm. I tried helping it by unraveling off some of the dead leafs, but it wouldn't do anything else and stopped growing for a few more weeks. So I finally hacked off about a foot off the top of the corm and IMMEDIATELY the next two leaves sprung up 4" before my eyes within a matter of minutes!!!! And about 12"-18" of new leaves came out within a week. What zone are you in and/or where are you located at? From my own personal experiance as a beginner with naners
, I'd definately agree with Sandy and cut back all of the dead stuff, and then some more just to be sure that you got everything that is preventing the new leaves from coming out.