The service manual is not "quite useless". It is quite clear that the Network Card is onboard. In the Service Manual, it says  Go to Integrated Peripherals and select Onboard LAN Controller,     Yes, if your Ethernet port blows in a lightening strike which happened to me and my Dell Precision M6300, then your choices are USB adapter or - for my case - an ExpressCard adapter. I bought a 10/100/1000 Gigabit Ethernet adapters of both types. And both types also work in Ubuntu Linux as a bonus.
I can't access the internet, it tells me there is an internal error. I opened the box, and I can't see a network card anywhere...  I've tried every fix that I know to connect to the internet, but it just tells me to plug in the network cable.... I've tried 3 different cables that are good, but to no avail .... Does anyone have any experience with the network hardware that is broken on this thing...?? I've tried to locate the part.... can't find anything on the Dell page other than a wireless PCI adapter ... any help would really be appreciated...! Thanks, Jim
Studio Slim 540 Internet connection problem...