Latitude D830 and dead Nvidia chip

Hi there,

I have a small business and a number of Dell laptops and desktops. I've had a faithful Latitude D830 for many years (since 2008 in fact). It's been through a number of upgrades of memory, hard drives and operating systems and it now a dual boot Windows 7/Ubuntu linux. It's long out of warranty, but I like it, battery is still good, keyboard fine and screen excellent, or was until a few months ago...

I started to notice the screen flickering in Windows when using dual monitors (laptop screen and also a Ilyama screen), and Ubuntu sometimes used to hang up, then I started getting the dreaded BSOD with the message that I had a problem with  nvlddmkm.sys and then occasionally some random dots over the screens. Then nothing, just BSOD on boot with the nvlddmkm.sys error. Ubuntu would hang at the login screen too. Dead laptop.

I did a bit of googling and found that there was a problem with the Nvidia Quadro 140M overheating and eventually expiring. I seem to have missed any warranty on this (my warranty is long out of date). BUT! I go into windows safe mode, disable the Nvidia driver and it works again. Also if I purge all Nvidia drivers from my Ubuntu system again it comes back, full screen resolution. Any attempt to install any Nvidia drivers takes me back to a dead system.

So, what I'm wondering is this: The Intel 965GM chipset that that laptop has has built-in graphics. With a dead Nvidia chip, am I now using the intel onboard grahphics or is the Nvidia chip only half-dead so that it works with the OS drivers but not Nvidias? All diagnostics point to the Nvidia chip as being used but I have my suspicions. Can' t seem to disable the Nvidia chip from BIOS, so is there a way of disabling it and enabling the 965GM chipset graphics?

I like this laptop a lot, so I'm pleased it's working again, and I assume any repair will be uneconomical, but I'd be interested to know what's happening.

Dean