(Image1)
3 motherboard replacements we have received for GX240's booted up by default in manufacturer's mode
In this mode the default boot method seems to be via Network (probably for mass imaging purposes)
Alt+F exits this mode
^This is all fine, I just wanted to make note that we've never received replacement motherboards in this mode before

All 3 of these boards displayed the random string of characters at the initial BIOS screen. Again, this is not normal
The random sequence is in the Owner Tag field
(Shown in Image1)

(Image2)
Notice here that the Service Tag is gibberish

I've been in contact with Dell recently and found out that all of the above can be reset with the Asset.com utility
link