what is wrong with my sxpr603?

I have a technics sxpr603 digital piano. I can turn it on and play it for about 10-15 minutes then all the stops playing and the blue screen goes to just blue no words or anything. I can turn it off and let it set for awhile and turn it back on everything is ok for another 10 min. then it stops playing again. what could be the problem

ryjr45601
September 2010