Dead GPU Fan Header in Alienware 17?

I recently got an Alienware 17 after Dell had a deal on their Outlet Home laptops, and for the most part I've been really liking it. However, I'm now having a problem with cooling the video card and I just wanted to know what my options are. Here is what I've done:

1. I started off by upgrading the processor to an i7 instead of the i5, and that worked out perfectly. No problems, and I redid the thermal paste just because I like to do that sort of thing.

2. I swapped out the stock hard drive for 2 spare drives I had. They are currently set up in a RAID 0 array. No problems there either, and I reinstalled the OS and all the drivers.

3. After checking all the drivers, I noticed there was a BIOS update so I grabbed that too. I had A10 and the update was to A14. The BIOS update completed and everything booted up normally.

4. Finally, I took the heatsink off the video card to make a note of the part numbers and to redo the thermal paste on that as well. I had to remove the fan before taking the heatsink off, and that seemed to go fine.

5. After replacing the heatsink and fan, I booted up the laptop and everything seemed good to go. I installed Payday 2 so that I could run a few rounds with some friends. After about 5 minutes of gaming, the framerates started to drop A LOT and I realized that there wasn't any fan noise coming from the right side. The GPU temps got up to 94C while I was playing.

6. I pulled the back panel off and saw the CPU fan spinning, but the GPU fan wasn't at all. I looked at the connection and everything seemed fine. They were both 4 pin connections, so I swapped the GPU fan over to the CPU fan header and it started running.

7. I didn't really know what to do, so I restored the BIOS version to A10. The GPU fan still didn't spin up when connected to the GPU fan header.

8. The Dell diagnostic at bootup (F12) didn't find any problems. I ran it twice and both times it came back as all clear.

So that's pretty much where I'm at. To sum it up:

* The GPU fan seems to work when plugged into the CPU fan header.

* I have replaced the processor/hard drive/thermal paste.

* I'm not sure the GPU fan was spinning in the first place.

I just got this laptop and I really like it, but don't really want to deal without having a GPU fan. Have I voided the warranty by replacing the processor, hard drives, and thermal paste? Did I damage the GPU fan header on the motherboard somehow? I'm not even sure it was working in the first place since I never really stressed it until after I swapped hardware.

Thanks in advance for any help!