AX1200 - sudden, loud, intermittent buzzing

Hello, all. I've owned an AX1200 for about 3 years now. Two days ago, I noticed it making an odd sound that I initially took for fan vibration. The next day it had turned to a much louder (audible even with headphones on) buzzing that was obviously electrical in nature. I tried replugging all the cables and the usual troubleshooting to no avail, the sound would not go away. It's become much quieter today, but I can still hear it if my ear is near the exhaust and I know for a fact it never made this sound before - both AX1200s I've used have been prone to making an occasional, somewhat loud 'chirp' sound so this isn't the first time I've had my ear down there listening for trouble. I had a few questions.



1) Is this alone grounds enough for an RMA? I know AX1200s have a reputation for being noisier than Corsair's other PSUs, but this loud buzzing was new for my unit and I'm now worried it may be failing. I'll admit I'm paranoid about this after having a bad PSU destroy a mobo and processor years ago, but I still don't like to take chances.



2) If Corsair decides the returned unit isn't defective/buzzing isn't loud enough, are they going to keep the hold funds for a cross-ship RMA?



3) Living in the southwestern US, roughly how fast could I expect the replacement to arrive? Would I have time to wait to ship my unit back until after I had received the replacement? I need my computer for work, so I'm trying to minimize my downtime as much as possible.



Sorry for the length, and thank you in advance for any assistance.