I installed two 4GB DDR3 1600MHz modules in my son's Mac mini Core i5 2.3 (Mid-2011) that, according to EveryMac, supports up to two 8GB DDR3 1333MHz modules. This worked just fine, for a week. Then the mini just "died". It does not start at all. Can this have killed the motherboard in some way, overheating or something like that? Please help!