My PSU has been making a very quiet, high-pitched squealing sound ever since it arrived in the mail. It only happens when it's plugged in and powered on. I don't think I can hear it when the PC is on, but that could just be the fans drowning it out. It's not a grinding noise or anything. It's not a completely awful sound, but I switch it off when I'm done with the computer anyway.
This is my first build. Is this normal, or is the PSU about to go bust? It's been a few days now, and it's powering everything and the fan is spinning so I don't know.
Unless your ears are much more sensitive than average I'd say thats a bad sound. Give it a week, maybe two, to settle in and see if the sound goes away.
If not, I'd get with Antec customer support and talk with them.