Off Mode In 5 Seconds

I gifted a new computer to my cousin and he was having a problem with it. He yelled over the phone "It says Off Mode in 5 seconds".

I turned frantic with worry and researched using Google and found information on this at:
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/604806/page/0/view/collapsed/sb/5/o/all/fpart/1
This was a little scary since it talked about changing the motherboard etc.

I asked him quitely, did you switch on the power button behind the CPU and he said "Do you have one at the back too" and I knew that I have a chance here and asked him to check it and switch it on if it isnt.

Thankfully it wasnt and it worked. So next time you come across this message "Off Mode in 5 seconds", check to see that all the cables are fixed right and that there is power supply to the CPU.