Nvidia GeForce 6800 xps 600 problems

(posting this in both video and monitors forums)

I recently received my dell xps 600 with windows xp media center edition, 1GB RAM, dual core 2.8mHz processor, geforce 6800 video card, dual tv tuner, 1907FP lcd monitor.  Have tried dell support with no luck…so here goes.

The screen shows a very grainy picture, like tiny pixels dancing and sparkling. This makes JPEGs unviewable, movies unwatchable, games unplayable, unless I want it all to look like junk. Now and then when a lot is going on onscreen, the monitor begins to slowly flash with a purple hue all the way to a blinding whiteness before flashing and doing it again – this also causes the mouse to be unresponsive and the system to slow to a 386 crawl. Optimum resolution is set – 1280x1024, 32 bit, refresh rate is correct, although the grainyness and sparkly pixels is there no matter how it’s set.  Monitor self-test is fine, so I’m guessing the problem lies somewhere in the communication between the video card and the monitor

have installed latest drivers correctly - no help, have run video card diagnostics - no help, have tried video card tweaks and adjustments like gamma and color correction - no help.

took advice of dell support agent and opened the case and “reseated” the card – didn’t help. Tried putting video card into other available motherboard slot – no help.  Problem exists with either dvi cable or analog.

Dell suggests contacting nvidia for help…nvidia says go to dell for help since they built it.  Any suggestions for tweaks, adjustments, fixes, opinions will be greatly appreciated, or I’ll have to ship this beast back, because I’ve spent two weeks with my new $2700 computer doing nothing but trying to make it look right, and now it’s pretty irritating. Maybe someone with experience in the NvidiaGeForce 6800 will have some tips for advanced settings or something.  Thanks in advance.

Please don’t post links to troubleshooters and drivers and manuals…you won’t be helping me…I’ve tried it all.