The E-03 error code is a warning that there is a problem with the cassette take up spindle drive, this in most cases caused by a cassette which is sticking internally and so another cassette must always be tried. However if this still doesnt make any difference then the slip drive system could be contaminated with tape dust as this can happen if certain brands of tapes other than JVC, Fuji or Panasonic have been used, Maxell being an offender in this respect, but as you have just acquired the device it may have originally been faulty so that possibility must always be considered. About the only thing you can do without dismantling anything is with the aid of a hairdryer on its coolest setting blow a few 15 second bursts of air into the open cassette holder just enough until you feel the metalwork turning slightly warm, then leave it for about 30 minutes before trying it out. Should it accept the cassette dont try anything until you have wound the entire tape forwards then back again as that will help to remove any oxidisation that may have developed on the head system. Further more detailed info cannot be supplied as you have withheld your e-mail address, and this type of info HAS to go to a direct e-mail address for technical reasons.