I have not sent the P5Q motherboard in yet. I have time before my RMA expires. Instead I have tried some at night tests to try to still get to the bottom of this. I share what I have found:
First, I have a copy of the factory DVD of Windows Vista Home Premium 32-bit with Service Pack 1 hanging around. I figured I would try this first for 2 reasons. One, try a legacy Windows operating system (similar to Windows 7 in some ways) and also a 32-bit version instead of a 64-bit version.
Now, I clean install Vista H.P. 32-bit on another clean hard drive as well. I do notice that during the install process of Vista, during the last phase called "completing installation", the screen flickers about 4-5 times, but returns fine back to the Vista install screen. I am not sure, but I "think" this is "normal". I do not install any other Windows Updates or even any drivers
for the motherboard -- is this good or bad??? I figure I should have no issues if I just install the latest nVidia driver
from the website since each driver is more or less independent of each other. So I only install my LAN driver so I can connect to the internet. I download the latest nVidia driver from the nVIdia website, but I do not install it yet. For curiosity, I do about 5 reboots of Vista to see if this possibly happens with that static/blank black screen happens after the animated Vista progress bar screen finishes. It does not. OKAY! GOOD! To let you know, I checked the Device Manager and it states I am using, "Standard Graphics Adapter" by Microsoft, dated: 6/21/2006.
After returning to Vista desktop, I install that nVidia driver. Sure enough on the FIRST reboot, I get that blank/black static screen flashing back and forth, ending with the black screen. I reboot again, and it does it again. The third time, however it does successfully get to Vista's Logon screen without any flickering. After a few more Vista reboots, I never got that screen issue again.
Following what I did above, I reformatted the same hard drive and reinstalled a clean Vista Home Premium 32-bit again. Did the same as above. Rebooted several times without the latest nVidia driver installed yet, and things were okay. I installed the nVidia driver and it did that same screen issue again at the first Vista reboot. I rebooted the system a second time and then I successfully got to the Vista logon screen without issue. I believe after the 4th or 5th Vista reboot, it did it again. So it is random. It seems as time goes on with the Vista reboots under the same Vista installation, the chance that it happens decreases, but it can still occur randomly.
Now, I decided to try to uninstall the latest nVidia driver to see what would happen when Vista reboots without the latest nVidia installed. It should be fine I figure without the latest nVidia installed. There are 3 components that are installed with the latest nVidia driver as seen under "Programs & Features" in Control Panel. They are (1) "NVIDIA 3D Vision Driver 266.58", (2) "NVIDIA Graphics Driver 266.58", and (3) "NVIDIA PhysX System Software 9.10.0514". I uninstalled (3) first, then (1) without issues. When I uninstalled (2) last (The actual nVidia graphics driver itself.); at the immediate completion of the uninstallation, I was getting a very similar issue here too... ....with the desktop showing the nVidia uninstall dialog box somewhat distorted and sparkle-like flashing very quickly in contrast with a blank black screen!!! The only way I could get out of this is to reboot Vista. Sure enough, it was gone and I was able to logon with Vista without issues. I checked the Device Manager and the graphics driver that showed was the "Standard Graphics Adapter" again. I rebooted the Vista may times with the Standard Graphics Adapter and things were fine and no issues.
There are more tests I plan to conduct. It "seems it is pointing" to some issues between the latest nVidia driver and the 9600 GT. The motherboard involved in this somehow too?
I did try using my DVD drivers that originally came with the 9600GT just to see if the LATEST nVidia driver was causing the issue. I again did another clean install of Vista H.P. 32-bit on the same hard drive after a clean reformat again. Things were fine without any nvidia graphics drivers installed. Once I installed the driver from the DVD that came with the 9600GT, it did the same thing as well after my first reboot of Vista with that screen flashing issue. This is version 81.4 for Windows XP and Vista. So it shows that it may "not" be the "latest" driver.
The EVGA 9600 GT graphics card has been replaced and it is still doing it with this same series replacement too.
Any ideas or opinions you have?