to isolate the issue. i removed the power button from the motherboard along with its connector terminal/wire, removed hdd/ram/lcd cable/etc.
kinuha ko ang motherboard, power supply at power supply port with wire going to the motherboard.
pagsaksak ng power supply, 1 LED light turns ON.
shorted the power switch terminal to turn the system ON, no go.
took my rework station, 4/4 setting.
blew hot air on top of the video chip for about 3 minutes.
pressed the chip down gently.
reapplied silver thermal paste on processor and video chip.
replaced video chip thermal pad with copper shim.
plugged the AC adapter.
shorted power switch terminal.
it's back to life!
did the shutdown and power on process for about 20x now, still has not failed. it's still naked though...hehe!
AC Adapter is in good shape, never dropped at least a volt when system is ON.