Importance of PCB mounting screws?

[caphair]

I opened a monitor I was working on to find that some of the main board mounting screws were missing. The holes they go through have solder around them making me think the screw is necessary as a ground point to the chassis.

This made me wonder how important it is to have all screws mounted if say only one was used. If it affects anything how so exactly? My first thought is with all the switching frequencies it can create noise around some circuits?

[stj]

Re: Importance of PCB mounting screws?

it's important.
i'v seen monitors with cracked pcb's because of missing screws.
as for using screws to complete the earthing, yes - there are some tv's like that.
samsung comes to mind.