The E-03 error code is a warning that the cassette take up spindle is not turning properly, so try another tape. If however that makes no difference, then there isn't much that you can do as its really a case opening job to investigate the mechanism. It should be pointed out that using tapes "other than" JVC - Panasonic or Fuji can cause problems with JVC machines, TDK and Maxell being the worst, with Sony not that far behind, and its all to do with the types of tape lubricant these brands use upsetting JVC's rather critical drive system.