Hello
it may be relative
but I was starting to think about taking the macbook late 2008 aluminium to the service center in the city I live.
I did several times all the steps shown in this link, but nothing worked.
https://support.apple.com/en-om/HT201295
What actually worked for me is the experimentarion of making the steps given in the link and also letting battery out, pluggin the magsafe to the laptop without a battery installed.
It is on right now, guess gonna see how it goes.