I dropped my sony xperia its not smashed but wont turn on an the back felt warm can this be fix plz

system ui crashed and wont turn on - Sony - Comunidad

Sony https://community.sony.es > m-series > td-p
... Xperia Companion. This will do a clean installation of the latest ... August 2017.

August 2017. Keep getting " unfortunately UI has stopped working" message.

..

hi there.
not sure if this is your phone as you did not give model number.
but try this.
First method:

1. In order to switch off the phone hold down the Power button for a short while.
2. Afterwards go to Settings and then to Backup & Reset.
3. Then selec Factory Data Reset and tap Reset Phone.
4. Choose Erase Everything if you are sure you want to clear all your data.

More items...

SONY Xperia XA F3113 - How to Hard Reset my phone - HardReset.info

www.hardreset.info/devices/sony/sony-xperia-xa-f3113/
or this one.
Restarting andresetting your device Sony Xperia XA support Canada English
or this.
Restarting resetting and repairing Sony Xperia XA support English
or this.
SONY Xperia XA F3113 How to Hard Reset my phone HardReset info

Bring it in to a repair shop and have them replace with a proper OEM Sony glass back panel.

Try to change power ic.

Sounds like the battery is the problem here.

There is a solution by Sony for this problem.
Just follow the instructions: http://talk.sonymobile.com/t5/Xperia-miro-Xperia-tipo-tipo/TIPO-TOUCHSCREEN-FIX-PATCH-HERE/td-p/262920

Hold power button and volume up button at same time. while plugged into a charger.

there are phone repair shops all over the place that can replace the glass quickly
the glass is fairly expensive but there are different qualities that increase the life of the glass on dropping
ask around , get quotes and consider having a person with experience do the job as it takes very little to break the phone full stop

Standard charger only charge Li-Ion. X10 is using Li-Po. So, make sure it is compatible.

go back to the place where the screen was fittted as they have messed with the battery connectors