Hi, am new in playing keyboard... we have our yamaha E413, one time, we are playing and it is working fine which is plugged thru adaptor and suddenly while playing the power is off and cannot play the instrument. We suspected the problem is adaptor and we have let the adaptor inspected by electronic repair shop and they say adaptor is in good condition. We tried to operate the keyboard by batteries and the keyboard is fine and working. Please assist to advise what is the problem and how can we use it thru adaptor. Thank you and hoping for your feedback that can help us.