I purchase a sonnet Encore/ST G4 1Ghz cpu upgrade for my G4 400 AGP. After upgrade, it did not startup, and of course, no startup sound. Does anybody have similar symptom on this? Would the power not enough because i have a GForce4 Ti installed? After the failure, I put back my G4 400 cpu on my Mac, but it freeze and freeze and freeze.......omg whats happened? should i need to put addition thermal plate? or........any advise?