E-03 is always an indication that there is a problem with the cassette take up spindle, if the error still shows up even with another tape being used then its obvious that the spindle is not turning properly and which will require a more detailed examination, this only possible by separating the casing. Although this may, or may not apply in your particular case, it should be pointed out that only JVC - Panasonic or Fuji tapes should be used in JVC camcorders and never Maxell or TDK tapes, as in service circles its common knowledge that using these brands of tapes can frequently be the cause of drive problems on JVC devices, this due to the composition of the tape dust deposited on the mechanism from these brands. As a long shot, with the cassette holder open you could try blowing cool air into the mechanism for about a minute or so with the aid of a hairdryer on its cold or cool setting.