Help Dell D620 Blank Screen

Hi all. Hope someone on here can help me.
Wanted to upgrade memory on my Dell D620 from 1gig to 2gig. Got the memory installed, ran Dell system check, all ok.
Loaded into Win 7, ok. After 1 min or so screen when blank withoout me noticing it so rebooted.
Loaded up ok, when into device manager and saw Nvidia Quadro NVS 100m has been disable with code 43. Started getting line on screen so I shut down.

Now when I boot up, I don't see anything. Back light comes on and system seem to be running but black screen.

I have tried the following but still getting blank screen.
1. removed new ram and replace with 1 stick of old.
2. unplug cmos battery, left for 10 mins
3. ran with no ram and battery, plug in main.

Another thing, while I had the keyboard up and started, I notice the fan dose not spin. Should it spin on start up like a desk top cooling fan?

I will gradly take any advice or help on this, don't want to loose my Dell.:Oops:

If it isn't running with your old ram in the old configuration then I'd say your mobo is at fault. Unless your old ram suddenly went faulty at that exact time.

The CPU fan should spin up regardless of if there is any ram in the system anyway, weird that it does not spin, points to motherboard again.

I been searching around and it seem like a problem with the nvidia chip. Took it apart and resat cooler with AS5 applied.

Put it back together and it booted up fine, left it for 1 hour or so went back to start it up again. Nothing screen blank again.

So I am thinking it must be the video chip, don't suppose anyone know a fix for this.