Inconsistent video problem

Hi – I am quite sure this is not the right forum for this issue, but maybe somebody can tell me where to go (lol). I have what I have to call a major bizarre and headachy problem. My hardware is listed below.

My monitor just stops working occasionally on my home desktop. I mean it is 100% blank when I boot up. I have not been able to isolate the issue at all. Here are some of my findings:

· I have the display on a USB KVM switch. The other computer that uses the monitor has never had a problem. It is my work laptop, so it is an external display for the laptop.
· Since the monitor works on the laptop, I am thinking the problem should not be with the monitor itself, the monitor’s power cord, or the analog video cable between the monitor and the KVM switch. These 3 components do not change when I switch between computers (the desktop that has the problem & the laptop).
· So I am looking at the desktop to monitor connection. Although I guess it is really the desktop to KVM connection. These seem like the possible problem components to me:
o PCIE slot
o Video card
o Video cable connecting desktop to KVM
· I have switched everything around over and over again and it has made no difference. I changed PCIE slots, changed video cards, directly connected the monitor to the desktop (eliminated the KVM), changed monitors. I think I have tried every permutation of these components. No luck.
· Perhaps strangest of all is that the monitor suddenly will start working with the desktop. It will work for a few days. I can see no particular rhyme or reason. I did notice this last time that my PC was acting very squirrelly (how’s that for a technical, descriptive term) and I restarted it. My network connection was flaky. Some videos would not start in WMP. Others would.
· One problem is that the monitor stays 100% blank when I reboot. I can’t even get to the BIOS setup screen.

Since this is so inconsistent and only affects the desktop, maybe it is some kind of short in the mother board. If so, it is unfortunately getting way out of my hardware league.

If this mishmash of information makes sense to anybody, I would appreciate any suggestions or advice.

Hardware:
· Homebuilt desktop
· MOBO: ASUS Rampage formula
· Viedo card: ASUS EAH4670/DI/512M/A Radeon HD 4670 512 MB 128-bit GDDR3 PCIE
· OS: Windows 7 Pro
· Monitor: Samsung SyncMaster 215TW
· Processor: Intel Core 2 duo E8600 Wolfdale 3.33 Ghz Model BX89570E8600
· 4GB of RAM. OCZ Flex EX 4096MB PC9600 DDR2 1200MHz (2x2048).


To anybody that responds: if possible could you let me know with an email at my work address eliot.tow@ge.com since I don't know if I will be able to access my home PC.

Thanks for reading this,

Wooleysdad