It depends, in extreme cases I am sure they could if they desired to, or if you are not aware of clearing the BIOS before sending in, but generally, NO.
PC parts are a commodity, and generally, the industry does not try to repair them, just grabs another off the assembly line since it is more efficient use of resources.
I mean one hour of tech service trying to repair a card runs the company anywhere from $75 to $125 per hour, so it is better spent doing more productive tasks.
Sure the do a quick diagnostic on them, and if working may relabel it for refurbished, but I do not envision them isolating the bad mem chip or GPU and replacing it to resale as refurb.