iPhone 6s+ looks dead but GSM works
My iPhone 6S Plus is dead. When connected to charger, charges continuously at 0.5A. Checked the display connectors and all looks OK. The battery shows a constant 3.6v (not 3.8v).
iTunes recognises the device when connected but can't grant access on the phone because of dead screen.
Long press Power + Home has no response. Volume keys, power button, silence rocker have no response either; no vibration or sound.
However when I call the SIM card on the phone, it rings all the way.. no vibration or ringer on the phone. Not able to pick the call either (maybe digitizer is not working either?)
Even when I send an SMS, it gets delivered instantly (delivery report).
Phone seems to power and register with network. I don't think it's just the display since there is no response from phone.
When I hold it in front of a camera, I see the proximity sensor IR.
What could be the problem? No water damage or physical damage, took good care of it. Stays registered to network even when not plugged in to the charger so the battery is able to hold it on.
Any help would be greatly appreciated.