tablet wont turn on

[Dan71]

I have got a tablet don't know what make/model when try turn it on the android sign comes up on screen but then switches itself off again anybody have any ideas what it could be I got it for free will it cost much to repair or am I better buying a new one

 

[mmike123]

my tablet it sed at first that my sistums wore down and wouid never gave a chane to do my stuff on it any ideas wat to do?