Asus laptop n551jq won't turn on

[Mehdi_24]

I have taken out the battery.
1. When power cord is plugged in:"power indicator" led (under light bulb sign) turns on all other led's are off including led of the power button. There is no fan noise. Screen is blank. Hard drive led does not blink. After a few minutes the heat sink under the Wi-Fi card becomes really hot.

2. When I pull the power cord out and hold power button for 15seconds-3minutes and then plug the power cord back the following things happen randomly: (a,b,c)

a) What I described in section 1.

b) "Power indicator” turns on, power button led turns on. "airplane mode” turns on I can hear the fan noise. Screen is blank. No hard disk activity.

c) "Power indicator” turns on, power button led turns on. "airplane mode” stays off. No fan noise. Screen is blank. No hard disk activity.


I have tried:
Reseating RAMs , connecting external monitor (nothing there).Tried different charger. removed Hard Disk, DVD ROM and even SSD
And another thing:
I post it to warranty (It cost me 33$ ). Laptop turned on by itself there. they told me there is no problem that we can see and they sent it back to me. It work about 20 days and now it has the same problem. I think this problem occurs when laptop goes to hibernation. Two days ago it turned on randomly (that time I plugged power cord while I was holding power button).
Please Help me. I am a PhD student and my hole life depends on this laptop.

 

[Mehdi_24]

MERGED QUESTION
Question from Mehdi_24 : "How to diagnose a modern laptop that won't boot?"

I have a laptop that won't boot. In desktop computers we can find problem source by listening to the beeps. But what should we do when it's laptop? Is there a serial port that gives out information about what is going on in background? or something like that?

here is the problem that was explained earlier:
http/www.tomsguide.com/answers/id-3474526/asus-laptop-n551jq-turn.html