Sort of playing by ear here, but I think the codes in that area have to do with the memory.
First thing you might want to try is clearing the CMOS by unplugging the power supply, discharging the power supply by hitting the case's power button, and then putting a jumper on the CLRTC pins next to the battery for about ten seconds, then removing it before powering the system (shown in the manual on page 24:
link to manual if you need a copy If you are using Jumper Mode to overclock the system, you might want to set the JEN jumper, shown on page 18, to pins 2-3 to enable Jumper-Free mode. If the board doesn't successfully POST in Jumper-Free mode, I believe it'll POST in a "safe mode" on the subsequent POST, which could get you around any settings the board can't run (not that this sounds like the problem, if it was running games before).
If that doesn't help, then you might start by confirming that the memory's still all the way in its slot at both ends. If you have more than one memory module, you might try just one at a time, in the slot closest to the CPU, and see if it will work with any of the modules.