Toshiba satellite L50-A-1CU not powering on

Hello,

My Toshiba L50-A-1CU (I think the USA version is S55T-A5161) is not get any power at all.

Usually when I connect the AC power the orange/white battery led turns on. Till yesterday at night it was working fine, today morning I pressed the power button and nothing ….

I did the following troubleshoot :

Changed the power adapter, measured the output voltage from power adapter and is 19V as expected, pressed the power button for 30s , pressed the 'reset' button reachable with a pin through a small hole on the bottom for 30 s , I also tried to power on without the internal battery just with just the AC adapter plugged and again nothing.

After all the basics steps for troubleshooting, I took apart all components and tested without RAM, CPU, Hard-drive, etc, just the motherboard and again no light or power .

So I started to measure the voltage across the board and I noticed that the voltage from the power adapter is 0 V (should be 19 V) . Then I realize that every time I connect the power adapter the voltage is going to 0 V. I tested the same power adapter in 2 laptops (one of them is same as mine) and is working fine. So I guess that some component from the motherboard is in short and is causing the power to cutoff in order to protect the board ...

Board reference : H000053270

Does anyone has any clue from where I should start troubleshooting on the motherboard ?

Any help would be appreciated