Steam Deck seemingly bricked after attempted SSD upgrade

As the title says, my SD seems bricked after an attempted SSD upgrade. I already put in the old SSD and everthing else back in its's place.

It doesn't have any reaction to any button combination, charging LED doesn't light up if plugged in.

I didn't damage anything obvious. In fact, I already had tried the upgrade the day, everthing worked fine then I reversed it because it was late and I wanted to use it without having to reinstall everything. I worked then just fine , the issue came the next day when I wanted to upgrade for good.

Just from the technical aspect, what can it be if the Deck doesn't show any reaction whatsoever?

Thanks in advance