I just got a computer built about 2 months ago, and today, the PSU blew. It was an Antec HCG-620W Modular Gamer Power Supply. Is it possible it took out my $400 mobo too? And if so, would I be able to RMA the mobo too? Can Modular Gaming supplies still blow other parts of the system?
Good PSUs (and even most bad ones) will blow themselves up before they damage anything else.
Modular PSUs add one or two extra potential failure points (connections from main PCB to modular connector PCB and then the connections from modular plug to cables) but beyond that, there is little difference in their potential to blow something else up.