Corsair's TX, AX, and HX models are all manufactured by SeaSonic, which is why they're top-quality. The CX and GX models, however, are contracted out to lesser manufacturers and it shows with their higher fail rates and multi-rail designs. I'm fairly certain the only 650w units are TX.
That really svcks, BoonProtR3. Any component from any brand still has the potential to fail

don't let this keep you from trusting SeaSonic-manufactured PSUs in the future.
Those are the normal symptoms of a failed PSU, which normally is the result of a PSU being underpowered for what the system needs. Unless you had some crazy power-hungry SLI/Crossfire setup going on, there would be no reason to expect that to happen with your PSU within 3 years let alone 6 months.
As for your audio jacks, when a PSU fails it can damage other components along with it but it's unlikely to have caused that problem. If you have a custom system, try reinstalling the motherboard drivers. They would be on the CD that came with your board or available for download at your board's manufacturer's website.