Phone useless after upgrade to Lollipop

[Bodilh]

I made the terrible mistake of upgrading from a highly functioning KitKat 4.4.4 to Lollipop 5.1.1 yesterday.

Since then my Z2 have been total mess! The battery drains from 70% to 0 in two seconds flat, making the phone crash and I need to charge it to even turn it back on. Trying to use the camera will crash the phone. Trying to open Albums will make screen go black, Google maps won't launch and so on...

I've tried to go into Settings->Apps->Camera to clear the cache, but after 15 minutes of looking at the screen when my phone tried to calculate how much everything was, I gave up. I installed the latest version of PC Companion, and I can charge the phone via my (functional) computer, but PC Companion can't find the phone, so trying to repair via PC Companion seems futile...

I've had several people trying to call me but obvioulsy failing, since my phone dies and when I'm away from home I can't charge it constantly.

Does someone have any suggestions? I'd hate to need to get a new phone when I have one that I like(d...), and when it's just the upgrade that's ruining my phone.

Thanks in advance!

[Uliwooly]

@Bodilh

There might be another issue, contact your Local support to get the device inspected

[Rickard]

I'm sorry to hear that.

Even if PC Companion can't detect the phone, you may still be able to do a repair of the phones software as the phone is turned off when you do that.

Try to follow this guide and see if a software repair works/helps: software repair using PC Companion