try removing RAM, dedicated Video card, and HDD kung mag on ang mobo, if mag turn on ang fans, with beep beep beep, it means either nasa GPU,or RAM ang sira.
DS Battery Saver will work much better to prevent drain when you're not using your phone by Making CPU sleep if not in use. Haha Tapos install ka rin ng Greenify(Works on Rooted and Non-Rooted phone) or Juice Defender, wag kayo mag install ng DU Battery Saver/Battery Doctor etc. dagdag RAM usage...