Mac Pro 2008 Black Screen with cursor On Snow Leopard

[sycastro]

Updated to snow leopard and now get a black screen and cursor. Boot up in safe mode fine.
Booted up Command S, mounted the files system as writable then removed the following files:
rm /Library/Preferences/com.apple.loginwindow.plist
rm /Library/Preferences/loginwindow.plist
rm /private/var/db/.AppleUpgrade

Still black screen. booted in SM and performed apple updates. Still black screen. ran a disk check all fine. Removed ram and swap. still black.

What am I missing here? An help is greatly appreciated.

 

[OS6-OSX]

I use 10.10.5, 10.8.5 and 10.6.8 on my 3,1. With SL did you go up to 10.6.8?

 

[sycastro]

I have the SL 10.6.3 install disc. It boots fine on SB but black screen on regular boot. I don't get it.

 

[MacVidCards]

Bad GPU?

Turn on screen sharing and boot without GPU. If it gets to desktop on remote you have your answer.