XPS 1530 motherboard???

I recently contacted Dell about a defective webcam... the tech replaced the webcam and then he went on and replaced the whole motherboard as well???? Not sure how the webcam requires they replace the whole board...

My laptop is configured with a 8600M GT and was previously overclocked via rivatuner with 685mhz core and 2050mhz memory clock. I've been using those overclocks well over a year now just fine at those settings ever since i've bought the laptop, no problem a ok !!!
Now upon star tup with those same overclocks after about 5 minutes the nvidia.dll crashes !!!! I lowered the overclock settings and it still crashes!!! The only way to boot up now is to have no overclock at all, stock settings only !!

Also to note the shipping box the tech brought in had "REFURBISHED" labeled all over it... leading me to think they replaced my moboboard with a refurbished one.. .

While talking to the tech i also inquired about the nvidia chip heat die/packing problems... His response; all these " new" boards rolling out now have a fixed/stronger die and everything is fine... with the reburished board he just installed not sure how new that one is..

Anyway! My question is now what is up with the overclocking. Do i have a defective 8600GT ???


XPS 1530
8600 GT
T8300
4GB ram..