It seems to be a fairy common problem with Dell XPS M1330 GPUs which are NVIDIA 8400GS series.
I started seeing this problem few days ago after using this laptop for 11 months. I've very extensive experience with laptops and was wise enough to take a 1+3 yrs extended warranty plan since I know there are many more things which will go wrong with a laptop with the kind of travel I do.
The problem generally starts where the machine starts to hang at various times without any pattern. Sometime the mouse will stop responding for few seconds and then become active again and then the whole system hangs.
Ater few of such incidents, you'll notice that the machine won't start and you'll see the random color vertical lines (just like in the picture above). They'll start to appear from the left and thne slowly fill the whole screen and then start to disappear from the left again.
Some people have mentioned that it could be horizontal lines as well instead of vertical lines.
Although you might be able to boot successfully if you wait for sometime and might be able to work as well. For me, it didn't work for few hours even after I completed some display and other diagnostic tests but then the laptop worked fine for the whole of next day. And, same problem returned the following day.
Display Test: With machine in the off state, press "D" and the power button, release the power button and once the caps lock light is flashing, release the "D" button.
Complete Diagnostic Test: With machine in the off state, press the "Fn" button and power button, release the power button and wait for the top right to show "diagnostic..." or lights next to the power button start to blink and then release the function button.
All these test will be fine if its a GPU problem.
Sometime you are lucky enough to see the boot screen and actually boot the machine, but you might see randon "Blue Scree of Death" like the one here...
The technician showed up in two working days and replaced the completed mother board, the heatsink and fan assembly and I was good to go in 45 minutes.
They haven't seen any more problems with the updated GPUs but nVidia failed to mention if it was a problem with the GPU generating more heat or somthing in the GPU itself. But anthing which get hot (and hotter) will fail eventually.
