compaq pres 1500 power up problem

i have a compaq presarion 1500 WITH power on problems..

I have been using it stationary..because if i tilted the lcd panel it would power off..
it seems worse..now…the ac light comes on..but now when i puss the power button to fire it up..it powers down..i wait a couple of minutes..the ac light comes back on..same thing..

maybe you can pinpoint problem..thanks
joe