Hi guys! I'm trying to swap processor on cMP4,1 and getting failure. Need your help. First of all, I'm doing all towards to the instructions. Using this one: http://www.youtube.com/watch?v=Ng34AVZS8Aw But after I've reinstall Heatsinks on new X5650, I've got RED LED CPU B error. I've found out this video: http://www.youtube.com/watch?v=YAdgT-hJuXU The trouble is in HC power connector. So, I've get it out of the HC case and plug it right away before put HC down to processors board. Now it's fine – there are no LEDs inside. Only front LED flashing periocally. But… There is no Chime sound and Mac Pro doesn't start up. I've made firmware update 4,1 -> 5,1, of course. And put 2 x8Gb ram PC1333 in 1 and 5 slot (for both processors). Please, tell me: 1. If processors or their connectors on the board are damaged – there should be any RED LED or indication? 2. Did you have such a case when swapping your CPU? Need an advice, guys, please help.