I have never heard of this problem but

Subject: I have never heard of this problem but
Name: Bob
Date: 7/7/2005 6:09:58 AM (GMT-7)
IP Address: 68.43.168.23
In Reply to: Oops, hit enter posted by Ben
Message:

I have a few questions for you.
Do some of the fans & drives power on even when thou it won't boot ?.
Is this the second PSU you tried ? thou new could be bad
Does that video card need a special plug plugged in for xtra power ?.
Is CMOS setup set right ?.
I will ask a real stupid question is the case possible of being an old AT type ?. wrong switch type if it is.

BTW I am not sure what OS you & what you use your computer for but 512MB is not really alot of ram & that can slow you down alot.
Bob