The battery not holding a charge could in simple terms be the battery itself at fault, although this depends on whether or not when you try to charge it everything indicates as normal? if it does then its nearly 100% guaranteed that the battery is faulty. On the tape noise / chewing up the cassette etc, similar to the comment made about the battery it could also just be a sticky cassette that is causing the problem, this not by any means being uncommon! and especially so if a tape hasnt been used for a while, however if trying another does not help the situation it then indicates that the take up drive spindle is not turning properly for some reason or another (possibly error code e-03 showing?) and unfortunately something you cannot do much about without dismantling the casing to gain access to the drive mechanism, although you could try blowing "mildly" hot air into the mechanism for about 20 seconds or so.