Power Light is always on and will not boot
the Power Light of my Mac Pro is always on. I can switch on/off the Mac (when I push the Power Button, the 4 LEDs on the RAM Board light up briefly and then only 1 stays lit on-and the Fan also goes on) The same the opposite, when I push the Power Button for a short while, the one LED on the Memory Board goes off and also the Fan. But the power light always stays on no matter what I do. The only way to switch it off is to remove the Power. I have tried resetting the NVRAM, PRAM and SMC- sometimes I am successful ans able to start up, but then the next day no more.
Any suggestions would be greatly appreciated!