Internal post speaker won't stop buzzing

[Med]

I just installed a water cooling kit on my computer. A couple seconds after I turn on the power, the little internal speaker that beeps the post code starts emitting a shrill buzz. It almost sounds like a tattoo needle. I can hear the normal short single POST beep over the buzzing, and it runs fine, but it won't stop buzzing. Any ideas?

I've touched the waterblock, and it doesn't feel like the CPU is overheating.

EDIT: On my motherboard, the POST speaker isn't hardwired to the board. It actually plugs in to the board. If I unplug it, the buzzing stops, so I know it's not something like the chipset fan going out.

[Med]

Doh. Figured it out.

Since I'm using water cooling, I don't have a fan plugged into the CPU Fan spot. The motherboard has an alarm if the CPU Fan fails.