Mac mini won't boot up

Sat nite I was checking a couple of prods at mfr site.  Suddenly got a message that there's no signasl so monitor was going into power saving mode.  That's the normal msg when I haven't done anything on puter for a few minutes.  I hit the space bar, as I usually do, but didn't get a response.  

I tried that several times to no avail.

Tried force closing it then restarting-nothing. 

Disconnected it from the wall(several hrs) and reboot- nothing.

Green light not glowing; white power light working.  Fan not working.

PLEASE HELP  This computer is less than 6 mos. old.

Remove the monitor cable from the computer and from the monitor, i.e. at both ends. Then put it back in.

Hi Tom,

The monitor is not the problem, the puter IS.  Spoke to Apple live support who wealked me thru everything I had done, + restting P-RAM- nothing.  I have appt today MaSH 5:30 for hands on help.

Thanks for your time.

Tom's suggestion certainly seemed like a reasonable additional check, as the signal from the puter might not be getting from the puter to the monitor because the cable is not seated properly.

Did you try it?

Fan not working suggests a problem with the computer not the monitor.

Follow-up-

Went to Apple store puter didn't fire up; didn't work with their monitor.  Test showed that problem is in power mgmt system.  Repairs will take 3-5 days; estimated cost $450.  That much for repairs to a $700 product would be rdiculous. I'm really thankful it's under warantee..  2 yr extended waranty $100 seems almost reasonable- esp given all the problems I've had with computers.