Motherboard or CPU problem?

1 long beep is usually either a video or a RAM problem.

Make sure that the video connector for the monitor is securely seated in the socket.

Then, make sure that both the video card and RAM modules are firmly seated in their sockets.

(Follow ESD 'static' precautions when checking the video card and RAM!)

Chas

I thin Chas is bang on.

Another thing to consider. If you have an ONBOARD graphics chipset and a separate AGP card installed for a graphics boost, you may have a hardware conflict. If so, remove the monitor from the graphics card and plug it into the mainboard's monitor connection. Remove the graphics card and try a fresh install.

If you have more than one stick of ram, remove them one by one and try rebooting after each one is removed, one bad stick will be a headache, and yes I've found out recently it is common.

If you get no signal, the PC is either finding an error BEFORE the graphics card is enabled or it is due to the graphics card itself.

The CPU is not bad.
The CPU must function to produce the beeps.
Remember, the CPU processes the BIOS code to do the Power On System Test (POST) where it checks the various functions, and then calls the speaker routine to code beep the speaker, when it finds something wrong. (Of course it also generates the short beep, if everything is OK, at the end of the tests.)

Next, troubleshooting.
The most likely cause of the problem is, loose video card.
(Previously Mentioned.)

RAM causes this symptom almost only on system builds/rebuilds. Not on boots of a previously functioning PC. (Excepton! Components being blown by failing voltage regulator, in the power supply.)
There was a dissimilar metal corrosion problem in certain RAM module combinations on 386s and 486s, that caused boot failures on working PCs, but that is gone, under current systems.

So, first, reseat the video card.
IF that does not work, check the video card in a different PC.
If the video card is bad, check the ground connection of your wall plug!
(If the ground is bad/disconnected, induced switching surges will eventually blow the next video card you install in your PC.) Also check the power supply voltages.
If the video card is good, Ouch!
Do you have access to a "POST Card"?
Since this MB has two ISA slots, you can use an ISA "POST Card", which are almost free, since they are so out of date. This will give you a lot more information on where the problem is, since the Beep Selection of this Award BIOS is very limited.
Another test you will want to run is, to install an old ISA video card,(Take from an old 386 or 486.) and try to boot on a floppy. If this works, FLASH the BIOS. The AGP/PCI detect routine has become corrupt.
As I remember, the 2 Meg flash ROM on this motherboard is one of the ones that are susceptible to a very rare BIOS virus. This is a BIOS swap with AOpen to solve. You should not get this far in the troubleshooting procedure. We are at 0.01% likelyhood.
Regards, Ch