Dell Internal NIC gone missing......

[#1]

I have a Latitude D600.  It was behaving well up until a few days ago.  I started getting odd Blue screens at startup, that went away after a reboot, then the Internal NIC started to disappear, even if I was on AC power. ( Its set via the power management to turn off when on batteries).  I disabled this option, and it reappeared randomly.  Then the Wireless card disapeared, as did the driver for one of the PCMCIA adapters. As this was a clone of the old drive that was in it, I saved all my data, and did a full reformat of the system, from scratch, and followed the DELL scheme for the driver install.  To my surprise the Internal NIC was not detected at all, although everything else works fine, including the modem.  Updated the BIOS, to no avail, and according to what I can find in the BIOS it should be active.  The green light is on, next to the NIC socket, but the odd thing is, when I disable the wireless NIC, the light goes off, and when the wireless NIC is transmitting, the Wired NIC orange light flashes, in time with the router lights, its like the Wired NIC is mimicking the wireless, or the wireless has taken it over.  I cannot for the life of me think what could be the issue, everything else works absolutely fine. I did think the NIC on these systems was connected via a daughter-board, but according to the service manual, this is not the case. A google search comes up with nothing.  Not yet stripped the lappy down, but thats my next port of all, see if anything is obviously amiss. 
Can anyone help??  I am stumped now.....

[#2]

What OS?
Try booting from a recent Linux distro Live CD (Ubuntu 9.10/Mint 8 etc) and see if they see the nic ok, if they do then it is a driver issue, if not possible hardware failure.
(http://www,linuxmint.com http://www.ubuntu.com to get the cds burn as an IMAGE don't burn the iso to a cd )

[#3]

I've got a D810 and had problems with the NIC going away when on battery.  I set it to never disable and have never had a problem.
I suggest going to the Dell website and downloading the full driver set for your model and installing the latest version of these.

[#4]

Thanks for the replys guys.
1.. Tried a Linux disk, still no internal NIC.
2.. Before I reformatted, I downloaded all the current drivers via my service tag, from the Dell website.
I suspect this is a hardware failure, but I have never heard of the NIC going south on an otherwise perfectly functional MOBO.  I will strip down the laptop this weekend, just to see if there's something like a dry joint causing the issue.....

[#5]

BIOS Battery?

[#6]

Shutter.
That is interesting. before this happened, I had an issue with a Blue Screen at startup.  and then a couple of drivers went missing. Rebooted,to the BIOS, and the clock was completely out by a few years.  Its been fine since however.....  Could try the BIOS battery, there cheap anyway...

[#7]

Thanks for the input guys.  Full marks to Shutter ( I think...)  Managed to find the CMOS battery, behind a panel in the battery compartment. Removed it for 15mins. Reconnected, and rebooted, and reset the CMOS clock.  Windows started up, and device manager showed a network device, but with a yellow exclamation mark, with the error... Code 10 Device could not start.  Rebooted again, and it seemed to appear OK.  Looks like then a worn out CMOS battery, and I have ordered a new one.  Heres hoping its the cause.
Thanks Again chaps.

[#8]

Glad to be of service !   

[#9]

Managed to check the CMOS battery, connections are very small.  Voltage was 8.1v, and should only be 7.1.  This would therefore indicate a faulty battery, as it would seem the internal resistance of the battery is at fault.  Anyhow new ones been ordered, see what happens.  After I put the battery back in afer around 6hrs of being out, internal NIC came back immediately.

[#10]

Well that didnt cure it.....  Even before the CMOS replacement, the NIC icon came up, and according to windows all well, and working properly.  If I connect a Network cable though, absolutely nothing happens, and the NIC icon continues with a Red Cross. Device manager reports no issues, and says everything is A-OK with the NIC.  Interestingly, If I try to make any changes to its setup, such as change from Auto detect, to 100Mbps Full Duplex etc, Windows completely freezes for approx 2mins, then comes back, and the NIC disappears completely.  This is very very odd..... 
Does anyone have any other ideas.  Again, the NIC lights work, but appear to mimic whatever the Wireless NIC is doing.

[#11]

Did you check the voltage of the replacement battery ? 

[#12]

Hi Shutter.
No I didnt, didnt think i would need to, but its an idea. It came from Hong Kong did the battery, from E-Bay.....
Will check, and post back later on.
Chris

[#13]

The new battery voltage is around 7.5-7.6v.  Switched on the laptop to send this, and the thing dosnt even detect the NIC now, but it did earlier on.

[#14]

Hmm.... this is weird.... Have just had a brainwave....   
I wonder if an electrolytic capacitor has gone duff, and it is working some times and most times not... !... this could prevent the circuit from recognising the battery is in circuit, and thus no NIC !...
(I am not an electronics engineer.... the above mentioned statement is only a (un)educated guess ! ! ) 

[#15]

Maybe shutter.  But to only affect the NIC.....  Everything else works fine.  Also the BIOS still appears to detect the NIC, or anyhow allows its options to be changed.  It is however odd, that even when detected it dosnt work.  I think I will have to admit defeat with this, and if I need a wired connection, get a cardbus NIC to use.  I however do appreciate your comments and advice.
Rgrds
Chris