who has used a screw driver to connect the prongs to turn on a computer without a case/power button?

Jumpers*

Only a fool.

Accidentally shorted two solderpoints on a Matrox GPU and switched on the computer I was servicing, taught me to check the main power before touching any components ;)

Done this.

I do it all the time on a old computer I use for my wallets. Been thinking about fixing it but it's probably never gonna happen 😁

had a skeleton setup like that once being too lazy to put components into a case. at first I would look to make sure I was touching just the 2 needed prongs. after a while would just run the screwdriver across them all real quick to turn it on lol

Asus was smart and included a power button on my motherboard :D