It may help to verify that your bios is version 213 for the G50VT. If it is not, then I would recommend to upgrade your bios. Or maybe just reinstall bios if it is updated because sometimes there can be an inconsistent file that puts the bios out of whack and then you will see weird issues.
As a side note, when the device manager lists that the "device is working properly", there could still be an issue due to the device manager is a general/basic system evaluation tool. Maybe you could go to CNET and download a free (but not one of the ads) system checkup tool and that may show you the issue.
You can google, "how to upgrade bios" and find a method that you like if you decide to do it. Some people teach weird so my how to recommendation may not work for you. Also, I would recommend to backup any data on your computer you want to keep. Go to the asus website and also download all drivers
(which Im sure you've done since you upgraded your wife's) and have them handy.
Hope this helps and good luck! Let us know how it goes.