My old black phone off.

I am W810C Sony Ericsson mobile phone, I use the original panels old cell phone into a black screen as off, but also to re-boot, the back panels are also moving out of action.Why ah?

redo the system under the cell phone to see if you look at the battery or whether there is anything wrong to ask the landlord is not lightly take you automatically to a few?
If so, 80 per cent is a bad chip.That was bad and cell phone batteries, a little loose! Software and motherboards can be discharged!! Again next phone system or look at it to see if the battery is not a problem

ask the landlord is not lightly take you automatically to a few?
If so, 80 per cent is a bad chip.

and cell phone battery that is bad, a little loose! software and motherboard Can be discharged!!

Thank you