MacBook only turns on if I connect the magsafe holding Power on buttom

Hi everyone, I have a problem with my macbook pro mid 2009

I´ve been using a non original battery

It worked fine until a few days ago when the macbook never turned on again with the battery.

Only turns on if I follow some steps

With no battery connected, I have to plug in the magsafe while i´m holding power buttom

Keyboard backlight off and cooler fan working at full speed.

Then if I turn off my computer, I can turn it on again only pressing power buttom one time.

If I disconnect the magsafe I have to repeat again the process to make it work again

If I plug the battery while the computer is working, automatically will turns in to power safe mode and only works if I disconnect everything and the process to turn on again is the same.

But!!! If I try to turn on with battery connected, it will never turn on!!! and when i disconnect the battery the computer turns on by itself!! with no power buttom

I´ve heard something about SMC system, so I tried to reset a few times, but i think that could be the SMC chip.

Any ideas???