Thanks for the comments so far. Its very helpful. I would add the other schematics but there is an image limit.
Pyr0Beast, there appears to be three potential LAN I/O's from a GBE LAN switch on the laptop mainboard. Only the first two are used, one for the on-board LAN and the second for the doc LAN. There is a dedicated Dock Connected? pin to determine the current state of if you are using the doc or not.
I'm going to pickup some flux and completely re-solder the socket I think. As well as replacing the surface mount capacitor that came off. My soldering iron is temperature controlled but not the best (cheap ebay job) but I think the suggestion of flux is a good one. Its not something ive used before but I think it sounds like the go. Where do you get replacement surface mounts like that? I guess I will need to replace the missing capacitor from somewhere.
In the PCB holes for the RJ45 connector, some pins do not have tracks either side but I know they are connected just from the LAN PIN definitions. With a multilayer board like this would there be tracks between each side of the board (layers in between) connecting these pins and if so is there a trick to getting the solder to stick inside the hole? I found a few of the pins would not take any solder on the initial inspection. If I unsolder the RJ45 and then clean with a solder sucker and then some acetone. Then use flux before solering? I'll try a hairdryer as well if I can find one.
Thanks for your help, really appreciated.
Just a note, due to the image limit I have put more images/schematics etc on
http://fullof.info/x61