I just received a hand me down system with the abit kn9-sli motherboard. After installing a new amd 64x am2 6000+ processor and a new hard drive...when I powered on the system...the systemboard speaker produces a continues but alternating beep and both the red and green leds are lit up......I don't know much about this motherboard...can you help?

Check your codes here:
http://www.computerhope.com/beep.htm

So after 5 seconds it won't come on again at all, or it runs for 5 seconds each time? What else do you have running on this computer? I'd suggest disconnecting all non-essential devices (hard drives, all but one memory chip, any expansion cards other than video) - if one of them has a short, they can pull down the power supply (regardless of the condition) and cause it to shut off exactly as you've explained. Let me know if that makes a difference (it obviously won't boot without a hard drive, but it will get far enough to see if that's the problem). If that doesn't make a difference, let me know and we'll try something else.

Try checking the jumpers on the motherboard. A lot of the SLI compatible boards have jumpers that need to be configured properly. You can find out the positions by checking the motherboard manual. Are you using an SLI capable video card or is the video onboard? I just ask because I had the same problem once while trying to install an SLI video card. I had no picture on the monitor and I couldn't figure it out for the longest. Finally I found the answer in the motherboard manual and it turned out to be a jumper that was set wrong. Hope this helps.

Try a new power supply. A flaky output voltage can cause all kinds of weird problems, but people often overlook the supply if the system comes on at all. The other possibility is that something on the motherboard is acting up, but I'd try the supply first. It's an inexpensive part, and you may be able to borrow one for testing from a computer geek friend, or even take one out of another computer temporarily.

Good luck and thanks for using Fixya!

A long beep signals that no memory is detected ; test the memory sticks and reseat them.

Are you sure the 4 pin connector is going in correctly? Some motherboards have an 8 pin socket, and the connector can be placed in improperly. The symptoms you describe indicate a dead short on the power line when plugged in.

Your mobo rans in Athlon 64 socket 939 compatable processor. The fastest processor there is that you can install in this mobo is AMD Athlon64 4000+ Socket 939 Processor. =)

ur mobo bios must be corrupted update it, this will solve the problem

Try downloading drivers for your motherboard, there may be an audio patch or some other driver you are missing

The problem could be a failed electronic component, and no cooling remedy will solve the problem. When some components fail, they result in high heat conditions.