aspire 5517 won't boot

acer aspire 5517 laptop will start to turn on (noise) for about 2-3
seconds then nothing
no display at all

the power on light will come on

we already tried what we found on the internet:
holding down power button 30 sec's while off (battery out)

we also tried resetting the wireless card + cd drive + hard drive

already tried starting up with only one ram at a time (both slots)

also tried connecting to external monitor