I have a dell inspiron 7570. It recently started giving me a hard drive failure warning.

When I boot to the dell diagnostic from the one shot boot menu I also get the following error:

"PCIe - Training error PCI tag-0100 VendorId- 10DE DeviceID-134D SVid-1028 SDid-07EA Bus 01: Link Degraded, maxWidth x4, negWidth x2, Slot 4"

I'm hoping for some help with identifying which actual hardware component this is referring to and if its something that can be fixed. I have experience with replacing the system board etc. so i'm not shy about having to take things apart if I need to. I just want to have an understanding of which piece I need to attack before I start mucking about.