[Q] Samsung Galaxy S3 won't turn on after so many ways (Literally dead) topic

Okay so I have my Samsung Galaxy S3 for about 2 years now and it's having a lot of problems for the past few months. At first it had the sudden death syndrome (when it suddenly shuts down and having that boot cycle on the Samsung logo) and now it's fine. But 4 days ago I was sleeping and forgot to charge my phone. When I woke up and plugged in the charger it was charging just fine. When the battery indicator shows 100% I tried to turn it on and nothing happen. Just nothing. I plugged in the charger back and still nothing. The screen was completely black. No vibrations. I tried to go into the recovery mode and I can't. I've googled some ways including taking the battery out, pressing the power button for a minute and put the battery back in. Still nothing. I've tried like ALL WAYS to turn it back on. I took my battery and put it in my sister's phone and it worked just fine. So I know it's the hardware problem and I know it's not the power button too because I tried to turn it on by using the charger (plug in the charger and pressing the volume down and home button) and still nothing. I don't know what to do because I have so many things in my phone and I don't want to do any factory reset (if possible) by sending it for repair. But if I still have some options please tell me otherwise I have to get a new phone although I really need my old phone back. Thanks.