I'm in the works of making a new build.
 
AMD 4000+ AM2 (single core)  
Asus m2n motherboard
Geforce 8800 GTS (eVGA)
1 gb Crucial ram (1 stick)
 
I am getting no signal to my monitor. But, all of my fans are running (cpu heatsink fan, gpu fan, other accessory fans.
At first I assumed it was my graphics card, so I popped in my old Geforce 7600 GT. Still no signal. So I put in my even older Geforce 6600 GT. Still no signal.
 
Secondly, I started to troubleshoot. I pulled out my ram and got a ram error beep on my computer case speaker. Changed what slot the ram was in. I unplugged all of my accessory fans. Still no result.
 
Third, I tried another power supply. I have a 500w generic power supply. I swapped that with my friend's test supply- a 500w Antec. I still get the same result- no signal on the monitor and all the fans are still running.
 
4th, I tried another motherboard from another friend I have. Same result, no signal to the monitor and the fans run.
 
Then I had my cpu rma'd. I figured since I would get a speaker error when I pulled the ram it had to be the cpu.  
 
But with the new cpu (same model, 4000+) I get the same result.
 
So here's where I am. My friend is going to see if he can find a coworker (he works at a local computer shop) with an extra AM2 processor, but he highly doubts anyone will have one since the store itself doesn't carry anything AMD. The only other thing it could be is the ram. I would have assumed this would be the problem, but like I said there is a ram speaker error when I pull the stick out.  
 
So in conclusion, these are my questions.
Do you believe the CPU is the problem?
Could the ram still be the problem even though there is a speaker error when the ram is not inserted?
If it is neither of these, what could it be? (remeber I tried another motherboard.)
 
This is really starting to piss me off. I'm about to enter Dell Hell  

Im guessing the motherboard is going through the integrated graphics it possesses, which it shouldn't by default (try running your monitor through the onboard).  
Have you connected the PCI-E pin in (I am assuming the 8800 GTS needs one)?
Do you have you monitor cable plugged into the graphics card, not the motherboard (I am assuming that you are not, but Just in case).

Why couldn't it be the monitor? Have your friend tried it with another pc? If it's not the monitor, I suspect the ram. Try it in each of the slot. If no go, then borrow a standard ram stick (vdimm 1.8v) from your friend. Regardless of ram size.

Try clearing the bios.

Did you plug in the 4-pin CPU power connector?

I'm with akhilles on this one.  Test the monitor.  As smalltime0 points out, be sure you're using the right video connector.  Regardless of signal, does the machine act like it's booting up (e.g. CD ROM starts loading for O/S install) ?

I should have pointed out I've tried 3 monitors. I know all 3 work for sure.

Put in one stick of Crucial. Hopefully you can go in the bios and set the voltage.
Try different memory if you can.