Hi, After a interrupted install process of HS...install was hanging hilmself..ends up in 1 hour of white screen..I had shut down the syst... after this my Mac Pro 2009 can't start or boot anymore. Keyboard, Mouse and Monitor dosen't correspond. It seems that all USB conn. are off. No light on the Keyboard (shift), just sometimes red light on the Mouse. Power botton glowing normal - fans and GC fans running normal... start sound didn't come .. just by holding power botton longer than 10 sec. --- >SMC ? -- I checked all.. but it dosen't works. P.S. I had cecked my syst. (10.9) ...on another Mac. - running and booting fine.. // No warning light LED's on the board!! Any help welcome !