Phone only works when connected to a charger.

[AC Question]

It's an old xperia phone. Works when connected to a charger, but when I get it out, screen goes black and the (softkeys?) are the only thing "working".

 

[B. Diddy]

Welcome to Android Central! The battery is probably dead. If you unplug it, and then plug it back in later and turn it on, does it wake right back up from sleep, or does it do a cold start? If the latter, it's probably a dead battery.

 

[qweasdqwe]

Once I plug it in, it turns on again.

The sony logo pops up, everything starts as supposed.

 

[B. Diddy]

Ok, so it sounds like when you unplug it, then plug it back in, it's doing a cold boot. If it was just asleep, it wouldn't show the Sony logo. Probably a failing battery. Does the phone have a user-removable battery? Try a new one, if possible.

 

[qweasdqwe]

Ok, so it sounds like when you unplug it, then plug it back in, it's doing a cold boot. If it was just asleep, it wouldn't show the Sony logo. Probably a failing battery. Does the phone have a user-removable battery? Try a new one, if possible.

Sure. The phone hasn't been used in a while, so a new battery should probably work. Thank you.