Do a CMOS memory reset and see if that helps.  With PC powered off and AC power disconnected locate the CR2032 battery on the motherboard. Remove the battery for at least 10 minutes.  Reinstall, connect AC power and try. If its still bad I would suspect the motherboard is bricked due to the new CPU installation.  
Recently i tried to do some light gaming on my usff Optiplex 790 and upgraded my cpu.I booted it up after replacing and 1 and 3 lights were yellow and were error message.  
After changing cpu to core i3 3240 1 and 3 error message.