phone was sort of 80% charged when I plugged it to laptop to transfer files. I remember seeing the screen went black with that charging icon (which doesn’t normally show when I plugged the phone to power socket or laptop, UNLESS the battery is all drained) and I thought ‘oh what’s it doing now’ and then it went all black and not responsive to anything. No screen, no vibration, nothing. I rang the smartphone and it wasn’t ringing - it went straight to voice message. Can someone please tell me what the issue is? I tried very hard to finally open the case and not sure what to do at all. Meanwhile i’ve been pressing the power button (with and without the lid) and absolutely no response..