If this helps anyone - good. I just had my A2000 suddenly stopped booting too. PSU would switch off after 1 second. Lots of mucking around and googling didnt help either. Long story short - I pulled the PSU apart and noticed not even the fan would not spin up so I gave it a spin by hand to see if it was seized. Nope - no friction at all. Then I turned PSU back on and it booted up fine! Gotta love this old technology. 