Hi,
I have a similar problem with my centris 650 running netBSD 1.5.2. 
I've found I have to disable extensions in sys 7.5.5 to avoid the 
"white screen of death". To enable auto restarts after power 
failures, I  just moved the entire extensions folder out of the 
system folder, but kept it handy in case I wanted to do more in 7.5.5 
than boot netBSD.

Hope this helps.
Tom

At 9:35 PM +0100 2/17/02, Thomas Bjorn Andersen wrote:
>Hi all,
>
>I spent most of last night trying to boot my Quadra 800.
>
>I installed 1.5.2 including the kernel and tried to use booter 1.11.3
>and 1.11.4a3.
>
>No matter what options I set, I get the "So I sez to him", and the
>screen changes to white and then nothing happens.  If I hit the debugger
>switch, I get the kernel debugger but I can't enter anything.
>
>I don't have any NuBus cards installed and nothing attached to the
>serial ports.
>
>Any suggestions?
>
>Thanks,
>Thomas


-- 
Tom Jernigan,  Oak Ridge National Laboratory, jernigantc@ornl.gov
Phone (865) 574-1166, FAX (865)574-1191