[HELP] Cannot power on Z7 Max

Hello all, hope I can get some help here. I was trying to boot my phone in recovery mode to clear the cache but the phone cannot be on at all. There is no response now when I try to on it normally. I've tried charging it but the phone does not respond at all. When I connect it to my pc, it detects it as a USB drive but says it has malfunctioned and cannot recognize it.

I'm not sure what happened exactly. :confused: Need some help~