Problems on laptops power switch

Hello,
Recently I'm getting a problem. When I connect the batter, my laptop gets start directly even though I don't press the power button. It actually happened 1 months before and the problem isn't solving.

One day, my little brother was playing game. Suddenly it got hang. Then I tried to restart by pressing power button. It wasn't working. Then I opened the battery, but it didn't wake up. Then I took the laptop to a servicing center. They told me that it will never be repaired. Then I thought everything is possible. I opened my laptop's casing by my own. Then cleaned it well. Put the memory batter open too. I didn't find any error on the circuit. Then I connected everything again. At last I could find that it can be powered up if I opened the power battery and connect that again. But there should be no memory battery which keeps the time and bios settings save.

That servicing centers people told me that it will never be repaired. But I had repaired. At least I could powered it. But the problem is when I connect the battery, it gets start directly even though I don't press the power button.

How could I solve it? Please reply me.