Played and completed both games. Yes they are fun, but so very, very overrated by its "fanboys". Its quite ridiculous... But you got to give it to Valve - you know you made a good money machine when you can get people to buy another game in hopes to unlock your product couple hours early.
DICE have said it will be the other way round this time. PC will be used to all its potential, and console will just have to make do with whatever they are capable of these days.
When I had a similar problem, I had 1 long and 3 short beeps. That generally means RAM / VGA failure - Was the latter for me. And yes, it would beep if its not connected, or not connected properly. Tell him to remove one of the RAM sticks if he has more than one, and see if that produces anything.
Its probably the motherboard gone south. Shouldn't be a problem replacing if he got it new.