One more update.
Today i tested with a 85w adaptor, and a good battery. Shorting pins 4 and gnd on the keyboard connector, the fan will spin, but will stop when i stop doing it.
Only with the battery connected, same thing, shorting pins 4 and gnd, fan spins, only with power adaptor, just give a little flick, both battery and power adaptor fan also spins, but i dont think the board starts up because it will spin only while im bridging those pins.
Any ideas?
It is pin 5 that is the keyboard start pin. Pin 4 is G3Hot. You should avoid grounding pin 4.
Since you know you have G3Hot then you should start by looking at pin 14 of the charger ISL6258. I suspect that may be 0V. It should be 3.3V.