My bet is a service center will try a simple thing then change the motherboard. The simple thing is a new CMOS battery not to be confused with the big battery.
When power cord plugged in, power indicator light comes on. When power button pressed, bower button light comes on and "Power On" indicator light comes on, fan spins for a second then stops and lights around trackpad come on but no hard drive activity light, no Caps Lock indicator light comes on when Caps Lock button pressed on keyboard and nothing shown on screen. When power button is pressed to shut down again (instead of just cutting off power via unplugging power cord and ejecting battery) only two or three seconds until power down as if error occured.
Attempted (and Failed) Solutions:
Removing power cord and battery and holding power button for 30/60/120 seconds then replacing power cord and attempt reboot; no change.
Remove RAM (1x 2GB and 1x1GB) one at a time and attempt reboot; no change.
Remove all peripherals other than RAM, Processor and Heatsink/Fan; no change.