I have in our recording studio Mac Pro. Last 2 - 3 months we have had problem, if we will start it, only light in start button will light, fans are working but nothing else, no picture in monitor and no start chime at all. When I push start button 5 seconds, it will shut down. Few seconds, I push start button again and all is normal, chime, light, fans and normal picture in monitor. Sometimes I must do this 3 - 5 times. And another problem, now very often Mac Pro can not find wireless mouse and keyboard, there is a sign: There is no bluetooth module in computer ( it is there). When I start again, all is OK but sometimes I must try many times. Can anyone help?