I have recently encounterd an odd problem. Whenever I shut down the computer I can not get it to power up again unless I unplug it from the power source for 10 or 20 seconds then it will sometimes power up normally, sometimes not . Then if I wait awhile or overnight it will power up normally. After it has powered up it will operate normally forever until I shut it down again. I always shut it down via tha START/SHUTDOWN mode.
Thanks for any suggestions.