Phone won't turn on

My google pixel phone works fine for last couple of weeks after purchasing a secondhand. Suddenly the phone dies and won't turn on at all. Tried charging the phone, and its warm but no vibration neither led indicator shows up. Tried turning on with power button and tried with power + volume down, still no luck, no response, nothing !

Before it's completely dead, the phone shown something strange with the screen, it turned black couple of times like a flickering or somthing but I can still feel the touch vibration on the screen, even though the screen is black. After the battery completely out, it won't turn on at all, no response, nothing!

What might happen to my phone?