Well...you didn't have 2 1TB drives before either.
I have a 1TB drive and I don't assume that it requires the same power as my 20/40GB boot drives.
This might be worth investigating: http://web.aanet.com.au/SnooP/psucalc.php
In my limited experience...a CPU that malfunctions (for whatever reason) is likely to prevent more obvious things...like booting....I would not pursue that suspect very long.
Along with various other obvious components, the two things that I know can make a system run amuck are the CMOS battery and RAM situations.
Hold on for inputs from others.