My computer will not turn on

My computer will not turn on

My computer has been having problems for well over a year now. A while ago it would not turn on unless it was plugged in so I started using my moms battery and my computer would turn on then but it would shut off later on. The battery works perfectly fine on her computer but not on mine.My computer will now absolutely not turn on at all. I'm thinking there is something wrong with the inside of the computer but I have no clue what.