Failsearching my hardware

We had a thunderstorm recently, and I was too slow with unplugging my computer and something got fried.

Upon opening it, I notice two lights flickering when I try to boot, these are the power and reset buttons that are on the motherboard. Thinking it might just be the PSU that's broken, I try with another. The buttons are now glowing with a consistent light, but the computer still doesn't start.

So, what part is most likely broken? The motherboard itself? The HDD is fine, I've tested it in another computer.

start with taking all cards and memory modules from the mobo and check if it makes 3 quick loud beeps (that means there is no memory) if it does, at least you know you have some functionallity, then put back the memory and reset the bios (usually by changing a jumper or removing the coin cell battery, also make sure you disconect the psu while doing this)if after reseting the bios still you arent able to boot, replace the mobo; if however you are able to boot, then start puting back and testing all the cards and periferals one at a time untill you can find the one at fault.

Alright, I'll try that, thanks!