computer components & hardware - Abit KV8-MAX3 Error State

I have an Abit KV8-Max3 motherboard with an AMD Athlon64 3000+ CPU and
768MB of DDR 333 RAM.

The system has intermittently experienced issues where the system
board speaker would begin emitting a two-tone low-high, low-high
repeating tone. Usually when this occurs, it starts during the the
boot process and I can shut down the system and reboot it and the
tones will not return. Occasionally it has required a couple of
restarts to stop the noise.

When I check the BIOS LED, it reads 7F, which appears to not apply
when I check the error codes in the manual.

Tonight, it began emitting the tones while the system was up and
running, and had been for several days. For the first time, however
it started, interrupted itself, started again, and so on for about two
minutes, then it began the repeating tones. I restarted and it
continued the alarm. This went on until I just gave up after about 10
tries. 30 minutes later, I booted the system and it began the alarm
immediately.

During the boot, the BIOS LED flashed through a number of different
codes, so quickly that I can't write them down, and then settles on
7F.

In the past, I have:

a) swapped video cards
b) changed RAM
c) swapped power supplies

Nothing has eliminated this condition.

Does anyone have any advice on what could be the issue?

Thanks,

Steve