Computer was shutting off, I cleaned unit pliugged back in worked great. I came back a few hours later and the power button was on but nothing was working, I tried turning off and nothing happened so I unplugged waited then plugged back in the fans work the light on back works and the dvd drawerworks nothing else, the power button won't come on nor will the monitor or keyboard. Any suggestion, thx for your help.
Failing PSU or Motherboard. I lean on mobo because of the fans spinning and the dvd tray opening
My bet would be on the PSU since fans are "dumb" devices that will start turning as soon as they have sufficient voltage, fans spinning is no indication that supply rails have reached power_good status. The DVD drive might not have under-voltage lock-out or not be powered by one of the rails that is failing to power up properly.
Computers and other devices with SMPS randomly shutting down or failing to power up is a very common symptom of failing output capacitors in the PSU.
Good news everybody! If you're an idiot like me there's a chance your PSU and Mobo are fine! Especially if you opened the case to clean/replace/expand/etc there's a chance you just forgot to plug in the power for the CPU. You'll have the exact same issue.