hoby25588 , you could try a resest, disconnect the charger,remove battery,press down the power button for 30 seconds, install battery and charger, power on system. The whistle you here may be a faulty fan,take laptop apart and give a good cleaning especially the fan and try, a can of compressed air should help blow dust, etc. out. If fan is still not functioning properly replace it, as it can cause issues. If it is not a whistle and computer is beeping, these are error codes depending on the amount of beeps. Use the link below for explanation of beep codes and possible fixes. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
http://blog.parts-people.com/2014/06/27/dell-inspiron-15r-n5010-beep-codes-diagnostic-indicators/