HELP!!! Laptop won't turn on no lights!

Hi there, I have had Sony Vaio VGN-N19VP/B for over a year now and this morning I went to open the lid and turn the laptop on and there were no lights or any response.
I took out the battery and put it back in to see if the connectors were loose but the problem remains.
I checked to see if the AC cable was working, the light was off and then I checked it with my multimeter output was 19.61v
Under the motherboard where powewr cable from AC jack is connected I have 3.98V.
On the battery output from moterboard on the 3 pin is 2.58V
Sorry for my language 
What do you think the problem could be? Could really do without this right now

 

Can you also test without the battery plugged in to see if it powers up
If not, leave the battery out, leave it all unplugged and let it sit there for a bit before testing with power only

I assume it was charged up before you finished with it last night?
As you have already cracked it open, do you see a bios battery? Might also be worth removing it and testing it without it plugged in - I have seen a laptop not switch on because of a bad cmos battery in the past

 

Hi an thank you,
I’ve tested cmos battery (unplugged) and he has 2.56V.
The battery has been not charged in full, my girlfriend used laptop last night and she plugged in the wall charger when they shown less then 10% remaining power.
Couple mins later my machine  stopped running

 

hi,
Its something happened, battery led start flashing after I reconnect the cmos battery. hurry

 

Thank you for your time aj84.
Finally I’ve sorted out that problem.
Thanks