Black Screen @ start-up

Dell Dimension 8200, Dell 1900FP monitor, Windows XP Home, Symantec AV Client, Zone Alarm FW

When booting up from tower Start button, Dell logo is distorted and text garbled with symbols interspersed. Receive normal Windows XP display with timer bar running for about 10 sec, then monitor appears to shut down (1, 2 cycle and power LED goes to solid amber with a black screen). Diagnostic lights on back of tower are all Green and power button LED is Green. Cannot turn computer off by depressing Power button, have to shut power off at surge protector. When I reboot to another menu via F2, F8 or F12 the menu text is all garbled with symbols included. I can get into SAFE MODE, but display is muted and have sets of blue vertical lines in background.

Troubleshhoting to date:
1. Disconnected white cable from back of tower and verified expected floating self-check dialogue box with solid Green Power LED. This verifies proper monitor performance.
2. Opened cabinet and reseated Video card---same problem persists.
3. Attempted to reboot from Reinstall CD---unsuccessful. Only thing different is that I get a garbled "Press any key..." message initially, then to (F screen which is timing out a Start Windows Normal option. Always gets back to same symptoms as above with black screen, only this process continues to cycle.

What diagnostic can I run from SAFE MODE that will help isolate the problem? Or do I need to do a clean Windows reinstall? How can I get to this menu option with the Reinstall CD? Any other thoughts?