You have power to your main consumer unit - you don't have power to your secondary consumer unit. The secondary consumer unit is powered from the main consumer unit. So either the MCB in the main consumer unit is dead or a cable is loose - or if there is power leaving the main consumer unit but not reaching the second - you have a external cable problem. If power is reaching the RCCB at the secondary unit but not getting through then you have an RCCB or cable problem at that unit.
Sorry to be so blunt but unless you're prepared (confident and competent enough) to take the cover of the consumer unit(s) and start observing and testing you might as well stop posting here and call an electrician out.
No good just thinking, my first step would be to eliminate it and use the two test buttons to prove power at the two boards, if the the other stuff in the games room works that would confirm the supply to the second board and discount any problem within the house