Cannot recognise or detect battery

Hi,just dug out my old psp2000 but it won't run on battery. I've tried for days.

I am sure its not the battery because it worked on another Psp. And i tried 3 batteries on it, all don't work.

The psp runs fine with ac power. It charges the battery (orange light) but for a minute or two only and then cuts off.

Running on battery only is impossible.

Is there a way to change the battery pin? Or do i have to change the board? Cos it might not be worth it. Thx.