[AC Question]

A year ago I decided to upgrade my OS to kitkat, everything worked perfectly for quite some time. Then, I decided to upgrade again to Android 5.0 (Lollipop) yesterday, after updating, my network signal is not working, my browser also not working (even some options from my settings). Since i still have the previous zip file of Kitkat on my sd card so I decided to downgrade from my previous OS. But now, my phone cant put on recovery mode (Vol down+home button+power), and worst my phone doesnt turn on at all after repeatedly putting my phone on recovery mode, the only thing working is the dowload mode (Vol down+home button+power) but Odin cannot detect my phone whenever I connect it. Please help ((