Correct, these were from old labs that we recently upgraded (new mac minis, soooo much easier to store). Some were loaned to students, the rest were sent to surplus.
Unfortunately, a lot of them had logic board failures (i'd say about 13) causing artifacts on the screen. Had to e-waste those after removing the hard drives.
my bro has a white iMac like that, it does have artifacting (usually in the background of the menubar), but the dang thing keeps on chugging. It's been years since I first noticed that lol.