I_have_A_MD

Hi Just had a few questions in regards to the MZ-NH600 Firstly, the MD plays often plays up, particularly in pressing the stick to go right. Sometimes instead of going to the next track it will go backwards. Can anything be done about this ? More importantly, I've heard some mics can support the line-in option. MZ-NH600 doesnt have a mic-in . What exactly am I looking for in the mic to be sure it will be supported by the line-in. Or will I have to buy a battery module. I wanted something to record live music hopefully under $100 Aus. Often the music would be played without any speakers around. So it would still have to capture it. Would the quality be as good as something like a MZ-NH700 recording through the mic-in ? Thanks for your help.