I'm experiencing this exact problem with my A7V8X
Bob, do you have any new information regarding this problem? I see you started this post back in March and I'm curious to know what you did to resolve this issue.
I just replaced my MB,CPU & RAM. I bought an ASUS A7V8X, an Athlon 2600+ and 512 MB of Kingston CAS 2 RAM. My machine was working perfectly before I upgraded. I was running a 1700+ on a Soyo MB (Via KT133 chipset) with 384 MB of RAM and a 250 watt power supply.
On my first boot attempt after installing the new parts, I experienced the exact problem you described. All the lights on the case and drives came on, but I didn't get a video signal. No beep codes and nothing on-screen. My first thought was that my power supply was insufficient. I'd been running the old 250 watt power supply that came with my Inwin case without any problems, but I know AMD recommends a 300 watt power supply at the very least to power Athlon processors. So I ran down to comp USA and dropped 60 bucks for a new 400 watt power supply. After I installed the new power supply and tried to boot the computer... no dice. I tried hitting the reset button a few times and power down then rebooting, still nothing. Then I went to the kitchen to grab a cold one and when I got back to my office the computer had booted into CMOS. It displayed an error in CMOS that my processor was configured incorrectly and to check my settings. I checked all settings, everything looked good. The board was in jumperless mode with everything set to "auto" by default. I hit F10 and the system rebooted.
The thing booted just fine after that and spent the rest of the night installing drivers and tweaking the pre-installed OS for the new components. I thought I was in the clear because I didn't seem to be having any more problems. I installed all kinds of software and did several reboots that evening without further problems.
The next day when I tried to boot it up I encountered the original problem I had experienced the day before. All the lights came on and I didn't get any beep codes, but there was no video signal. It just sat there. I tried rebooting several times and finally after the 10+ attempt it booted right up into windows... wierd.
I have since torn the computer apart and put it back together again with the same results. If I power it down, I have a real hard time getting it to boot up again. I'm reluctant to call this a "Bad CPU" problem because it does work after several attempts, right along with the rest of my harware. In my experience when you have a hardware problem the component normally works or it doesn't, especially when talking about CPU/MB/RAM.
If anyone has any has some information or suggestions regarding this problem, please let me know.
Thanks