Question Screws for motherboard

[Sblair5]

Hello, so my 14 year old is building his first computer. He used the wrong screws for the standoffs. He can neither tighten the screws nor take the screw out. They are wedged. The motherboard is not tightened down to the case. What are the repercussions?

 

[Dark Lord of Tech]

Shorting out the system , possible to damage to components. You need the board to be stable and secure.