7VAXP System Temp. Sensor and Dead LAN

I'm running a 7VAXP with a 2500+ (overclocked to 2250=173x13), Volcano 11+, blue Zalman northbridge heatsink, and a 120mm fan blowing on the CPU and northbridge. The BIOS reads my CPU temperature around 46C under load and the system temperature as 50C. Since I have good airflow in my case, could this be the northbridge temperature? Or even worse, could the sensor be nestled in between the MOSFETs?

Also, I had the motherboard back in its box for a couple days while I worked on my case. When I got the computer assembled again, the onboard LAN didn't work. The lights on the network switch light up when it's connected, but I consistently get 100% packet loss when trying to ping the router. I have tried two different ethernet cables. Could my LAN be dead?

im 99% sure The system temp is taken directly from the northbridge

Update on my LAN problem. I don't think the hardware is really 'dead', because it pops back up every once in a while. My specific problem, now that I've narrowed it down some, is that the BIOS doesn't always see the LAN controller, nor the Promise RAID controller. Now for some reason, certain features don't even appear in the "Integrated Peripherals" menu. I used to be able to turn RAID and LAN on and off, but now there's no trace of them. I haven't changed the BIOS version in a while; it's still at the latest F13. After I identified the problem, I tried to restore the BIOS from backup, but it didn't change anything. Changing my FSB and core voltage didn't do anything. Help, please! I need to get my network port working again!

**HELP!**
Alright, this has really escalated. A lot of my southbridge functions are seemingly nonexistant. USB, Firewire, RAID, LAN, PCI. My audio, floppy, PS/2, and normal IDE channels are fine, though (I have no means to test the game, serial or parallel ports, but they appear in the BIOS). I was thinking this all started when I replaced my northbridge heatsink, and now I realize that was when I put my old NB HS on my southbridge. I used non-conductive Arctic Alumina epoxy, so it shouldn't be shorting anything, but I can't take the HS off to check. The heatsink is a little big for the SB, but I'm quite sure it's not touching anything else. If anyone has any ideas, or has had this problem, please let me know.

I am going to keep posting this number until it becomes a sticky.

Gigabyte repair support in the US is 626-854-9338 ext 222 or 224

The only reason I say this is because I couldn't imagine any scenerio where another component would interfere with so many intergrated components. Even a nastily old PCI card should pull rank with it's DMA settings and be fine once the BIOS is done jumping through hoops. It's most likely an unrepairable hardware problem from what you have said.

Try tech support first. I don't have their number, but I'm sure the folks from the above number can either give it to you or forward you to the proper extention.

Sorry mate.