I recenty got a three Apple Disk II 5.25 drives (AM2M0003). I noticed that one drive has an RF shield inside and the other two drives have the RF shield missing. I'm wondering if it's missing because someone took it out and forgot to put it back in, or was this something that was added/removed as some point in production at the factory.
The one with the shield intact has never had it's internal screws removed, while the other two with the missing shield show signs of screws being removed for servicing. So my hunch is that someone took the shields out perhaps?
Can someone please confirm if all drives are supposed to have these?
It looks like the aluminum shield is there to protect the logic board from interfering with the read/write head located under it.