Solved! Low volts

Solution
Some of the pins are used as a logic supply voltage to determine battery charge level, temperature, etc. Most laptops won't provide a charging voltage to the battery terminals if there is no battery present. This is to prevent damage to the charging circuit by inrush current or shorts. When you say "won't boot", will the laptop turn on, post, and then hang, or will it not turn on at all?
Some of the pins are used as a logic supply voltage to determine battery charge level, temperature, etc. Most laptops won't provide a charging voltage to the battery terminals if there is no battery present. This is to prevent damage to the charging circuit by inrush current or shorts. When you say "won't boot", will the laptop turn on, post, and then hang, or will it not turn on at all?
 
Solution
hp - 90% of there laptops contain nvidia chips

90% of there units die after 3 years or LESS because of it

relflow or new mobo to fix

symptoms: power on and cuts out, power on and no display, intermittent power up issues, random shut off issues etc
 





That's a kinda generic bunch of issues there. Theres's a dozen things that could cause those. I won't argue the nvidia portion of your statement, but it's not just limited to Nvidia problems.
 

yes thats it the video chipseems nail down