I have a X1950 Pro and the fan acquired a "grating" or "raspy" sound indicating that something might be amiss. I emailed them under their support option and received an e-mail back that asked for me to supply specific infomation, within the body of their correspondence, i.e. date purchased, where the card was purchased, and a specific model number that is found only on a sticker on the rear of the card. A week later, I had an entire heatsink/fan assembly. As it turns out, the fan for some freakish reason, stopped making the sound, so I have a spare fan should I ever need it. Based on their prompt response to my particular problem, I would conjecture they would respond in a similar fashion to your needs.
On the other hand, Diamond Multimedia's customer support is near non-existent.. never got around to finding a contact number or email, and when I found one, turns out it was an invalid email.. my email got bumped right back to me.. I'm going to try the phone number when I have time.
Yeah, diamond always rubbed me the wrong way from the look of their products, never bought from them. I have everything ready to ship but the $10 check for return shipping.
Bit nervous but phone and email support have been fantastic so far.