My smartphone is dead

I think it's dead. My Xperia Z1 is pretty old, so I thought this would come someday.

But is it really dead? It can do internet without WiFi. But it can't receive a call. Everytime someone calls, it doesn't get through, and somehow I get a short mail which says "You've got a call".

And when the charge is under 90%, suddenly it blacks out. I connected this to a mobile battery, and it almost worked, but imgur app is broken and it hardly upload a picture.

When this happened, I worked up to do some report of Japan for some gaijins. It's really a challenge for me. I don't like the timing of this. Something like this always happens in my life. I'm used to this kind of things. Probably all people have experienced something like that naturally. They say worst things happen at the worst timings. It's really true.

So I post this from my PC. I'm a PC guy, not a smartphone one. So I'm not sure my diagnosis is right. But I ordered a new smartphone online. It's ZTE blade v580. I bought it at 9700 yen. I think it's really a bargain.