I bought my son a Casio lk 100 keyboard on reverb. It came with old batteries in it that seemed to have leaked. Looks like it has not been played in a long time as there were spider webs on it! there was no power supply chord. The keyboard will not turn on with new batteries. Should I invest another 9.00 in a new power supply chord to see if it works? We are traveling and away for over a month and my little guy is missing his piano playing and lessons?