Pioneer Stereo Buttons Not Functioning Properly.

I have some problems with my Pioneer DEH 3250UB. Before there was a problem of auto volume up or down. Sometimes it automatically reduce volume to 00 and sometimes it increses the volume upto max. This problem got solved automatically.

After 2 days there is a different problem. No matter which ever button we press, the it does the work of SRC button i.e changing the modes from Tunner to Aux or Aux to Tunner and sometimes turns off when we long press any button. Even if we rotate the volume button, it change the modes or turns off the stereo. Please give me the proper solution.