reoccurence of magsafe failure

I have MACBOOK core2Duo late 2008 edition.System is just a year and a half old

Battery was not charging thus magsafe board was changed and problem got resolved. But after using for few hours display or video went. System was booting and I could hear the sound of drive and fan but video wasnt there. Than Dispaly came automatically. I thought it to be related to moisture.

Now after one week of repair again battery is not charging.

Now wat is the problem? is it the magsafe board again or the battery.

does Apple gives any warranty with MAgsafe board.

I found out thatMagsafe board which was replaced is not for my macbook(13"1278) actually it is used for 17"macbook pro 2.8(1296)

Wat damage it could have made to my system?

I got the repair done from Neoterique which is Apple authorised reapir centre.

Please help me