Question Stuck screw

[nice-s]

I just bought a hyper 212 halo black. I was just curious and wanted to see if the backplate would fit long story short, I put the brackets in too see if it would it fit. It did, however while I was unscrewing it it just wouldn't come . Every screw can come off except one. It's stuck and I can see it rotating from a small opening ( in the backplate) it just won't come off. How can I make it come off? It is stuck to the backplate,ive tried pliers, long nose pliers and a fork it just won't come off

 

[ex_bubblehead]

This is what happens when you crossthread screws and strip the threads off. Your only out here is to cut the head off the screw and drill the screw out, rethread and use a slightly larger diameter screw in that hole.

 

[nice-s]

This is what happens when you crossthread screws and strip the threads off. Your only out here is to cut the head off the screw and drill the screw out, rethread and use a slightly larger diameter screw in that hole.

Thanks, I'll atleast stop trying now