acer aspire 7552g problem

Please help.
When i press the power button acer starts but with no picture, just blank screen. No picture on external monitor as well.
I can hear the cooling fan, and then after couple of seconds it just stops (cooling fun). But the wierd thing is that green power button is on all the time, and laptop is on. No beeping sounds also. The green light stays on, its not flashing or something, just stays on. Finally i have to press power button to turn it off.
What do you think? GPU or maybe CPU?
Thx in advance.

 

It can be anything that prevents booting- apart from the CPU- that one is extremely unlikely.

Try removing RAM sticks one by one and testing each in the other slot. Once that is confirmed you may want to remove HDD and try booting from a USB pendrive and remove other devices (DVD, WiFi).

If none of those can be identified as a problem- it's most likely a motherboard itself.

 

Already tried several ram sticks but nothing. Tried also with HDD, DVD removal.... nothing. Didnt try to boot from USB pendrive, but i dont think it will work cause i can not even see BIOS screen when i press the start button.
So probably the motherboard?!

 

Probably that- mobo. You may try disconnecting the LCD cable in case there is a problem there (short circuit).

 

Already did, connect the laptop on external monitor but nothing Same thing.

 

Ok new moment
Because i am stubborn i investigated and tried few things more... I removed the small battery from motherboard and put the new one.... Now, after i turn on the laptop, somehow it did make change. Now cooling fun keeps on running all the time, but still no picture on the screen. Then i tried to shake some of the components and all i get is 2 short beeps. But not every time, sometimes i change ram module and i get no beeps but also no picture, and sometimes i get 2 short beeps, still no picture. What is oud and wierd is that i removed all of the components from motherboard but sometimes it detects dvd room(i can see light runing), and sometimes when the laptop is off i can still see the power button on even if laptop is off (???). Now i also remembered before (10 days a go) when i press the power button of and laptop did shut down, but later when i just put the adapter in the laptop the laptop just started running even i didnt press the power button and with removed battery.
So maybe a new perspective on things, or you still think its motherboard? I am convinced now that it is motherboard, but acting like this is crazy with no sense.
Thx a lot guys!

 

Are you sure that there is not short circuit or spillage in the/near the power button?
Still sounds like a mobo to me but it's not like I wasn't wrong before...