RacoonRider wrote:I'm not sure about EMI. Come on, the front of the case is made of plastic! And there are cases made almost entirely of plastic (laptops, desktop AcerMate series).
Laptops have shields over the component areas. Usually a whole network of shields.
Also on the backside of the keyboard. Is not the keyboard that needs that to be metal.
Cases come with steel panels behind the plastic and knock-outs for the bays. Those knockouts are -supposed- to be put back if you vacate a bay.
Some companies used to make them easy to put back in but so few people know enough to do it they quit making them that way to save $.
Even today companies that sell servers offer metal blanks to put in unused bays. High end case companies may also.
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Acer certainly does use shielding on their laptops.
Desktop AcerMate, I dunno. Never had one.
I have had or worked on similar vintage & style of other brands and they all had metal panels behind the plastics.
(Off the top of my tin foiled head: HP, PB, Zenith, Gateway, IBM.)
All the consumer cases of the time I recall (and now for that matter) had metal panels behind the plastics.
Acer may have been playing cheap-down games with this series.
RacoonRider wrote:For what I know, one of the purposes of I/O shield is I/O ports grounding.
Port shields (meaning those shields that don't come off the board) are well grounded to the motherboard already.
That is not the case with front ports. Especially cheap ones.
I think the tabs are to prevent the case and motherboard from being at different ground potentials due to an otherwise long path.
Wouldn't be needed if the mobo is properly grounded to the case but not all of them are so the industry assumes they aren't.
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