Screen flashing red up top for a while now

Okay so i got a Pixel XL from an auction lot and the first thing i did was to charge to see if there was any life. Sure enough a red flash was going off at the top of the screen but nothing has came out of it since the screen has been damaged when i got it.

However, i left it for charging for 3 hours now and it’s still flashing red. I can’t seem to figure out why it’s taking so long, could it be the battery or my charging port? I test out my cable from another phone so i know that wasn’t the issue. I tried turning it on but no sound plays and the flash keeps going. It stops flashing once i disconnect it but that’s all that i know about from this device. Tried connecting it to my PC, it doesn’t detect

What could be the cause from this?? Can anyone help me?