Basically the story goes like this: I bought a Sonnet Encore ST 1ghz but when I installed it I just got a black screen (no signal to monitor) when booting up, Sonnet thought it was faulty so I sent it back, on Wednesday night I upgraded from Jaguar to Panther and had no problems (with my G4 400), yesterday I received the replacement chip from Sonnet so I tried to install it and got the same black screen, I put the old chip back in took my RAM out and put it back in, I also changed my grapihcs card back to the orginal and now get these kernel panics.