Lots of Suspects

Hello,
I have read quite a few questions and answers on here, but I would still really like a more specific answer. I am building a new computer from scratch. I got it put together the first time, but it wouldn't boot. Everything looked fine, but the monitor was saying "no signal". I looked more closely at the different parts as it was running when I realized that the two, yes two, video cards were a little warm because both of their fans were not running. I thought maybe it was a motherboard/video card compatibility issue so I bought a new video card. I got the same monitor message, but the new video card (which is much smaller than the first two) has a working fan. At that point I decided to try a new monitor and cables which produced the same results. So then I tested the motherboard by taking out the video card and got no beeping. Finally I decided, after consulting the motherboard manufacturer as well as the video card manufacturer, that I would get the motherboard replaced.

I just got the motherboard back today and so I put the comp back together again.....and, of course, the monitor said the same, "no signal". I tried reset the jumpers, but nothing changed. I got online and read as much info as I could about the "no signal" message when I realized that I made a mistake the first time by not testing the processor. So I did the heat test and it was cool to the touch. This leads me to believe that I need a new processor. My main question is this.....should I test anything else like the RAM or whatnot before I send for a new CPU??? As far as I understand, if the CPU is cold, that either means it needs to be replaced, OR it means that the CPU is not compatible with the motherboard....is that correct??? Also, is it possible that the original video cards are compatible, but the defective processor kept their fans from working??? I ask this because I am on a 30 day return/refund/replace policy on all my comp parts.....which means that if the first two video cards should have had functioning fans....then I need to either exchange them for new ones or find different more compatible video cards. I would just wait and test the "bigger" video cards with the new processor to determine the problem for myself...but I may not get the new processor back before my 30 days are up....and the video cards cost around $250 EACH!!!, so I really don't want to miss out replacing them.
Here's a list of my computer's components:
Mobo: ASRock K10N780SLIX3-WiFi AM2+/AM2 NVIDIA nForce 780a SLI ATX AMD Motherboard
CPU: AMD Athlon 64 X2 7750 Kuma 2.7GHz Socket AM2+ 95W Dual-Core black edition Processor Model AD775ZWCGHBOX
The "Bigger" VGAs: MSI N260GTX-T2D896-OCv2 GeForce GTX 260 896MB 448-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card
RAM: OCZ 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model OCZ2G10664GK
PSU: KINGWIN Mach 1 ABT-1000MA1S 1000W ATX / BTX SLI Certified CrossFire Ready 80 PLUS BRONZE Certified Modular Active PFC Power Supply
Let me know if you need more details...i.e. Monitor, Hard drive, dvd drive...etc.
And I would really appreciate ANY help on this issue. :D