Xperia Z3 charging problem

[jamade]

My Xperia is going nuts... When the charger is plugged in it's jumping from 50% to 7, then up to 100, then 5, then 50 again, etc etc... If I take the charger out it beeps at me that the battery is at 5% or less and to recharge - but obviously when I do that it goes crazy again. I am using a proper Sony charger and cord. Any idea what to do? Thanks.

[Qatrium]

@jamade

Try pressing power and volume up buttons at the same time for at least 10 seconds (ignoring and restarts) until your phone is forced to switch off. Use an original charger to charge your phone while turned off, then start it when it's full.

[jamade]

Yep did all that. Now it won't turn on at all. Great. So not getting a Sony next time