Lenovo T430 Laptop won't start - dead motherboard?

The laptop was working fine until a few days ago when I tried to power on the laptop, even with the AC adaptor, it would no longer power on. I did just come back home from the airport, so maybe that had something to do with it?

I followed all the steps here: https://www.computerhope.com/issues/ch00...

After following some of the steps, when I hit the power button on the laptop, it would flash for a second or so, and then stop flashing. Nothing ever appeared on the screen

I then checked for continuity in the RTC battery, noticed there wasn't any, so I ordered a new one and confirmed continuity in it. However, the laptop still won't turn on, even after following the steps in the link above

I then removed the Hard disc, RAM, and WLAN. I then plugged in the AC without the battery, and once again, when I hit the power button on the laptop, it would flash for a second or so, and then stop flashing. Nothing ever appeared on the screen

does this mean the motherboard is dead? I have to take this to a repair shop or buy a new laptop?