I'm running out of ideas....

I have a computer here I just built:

AMD Athlon XP 3200+
512mb PC3200 RAM
80GB Western Digital harddrive
CD-RW
CD-Rom
Antec 430 PSU

I didn't list the motherboard because I've tried this with two seperate motherboards that worked flawlessly (both with this processor too) before this build. The motherboards are: MSI KT880 Delta and a Soyo SY-KT600 Dragon Plus v1.0. Both worked fine with this processor before this build.

For some reason, both boards give me the exact same thing....I power them up, computer sounds normal starting up, both beep once, but neither of them post to the BIOS. I've tried clearing the CMOS on BOTH boards by the jumper method as well as removing the on-board CMOS battery. It didn't help. Still get the computer turning on normally, but not posting.

Any ideas?

Edited to add: I should probably also mention that I even gone so far as to removing EVERYTHING from the board(except the video) and starting it up with nothing on-board to see if anything posts. I've also tried different video cards. All with the same results.

Make sure all the standoffs for the motherboard are in the right spot, I've seen people short out a board by putting in a standoff where there shouldn't be one.

Are you sure the video card isn't toast? Do you see a ram counter or anything on the screen?

I tried a different vid card too. Still nothing showed up. That second video card I'm currently using in my Vista machine, so I know it's not the video card.

All the jumpers and switches are set properly on both boards. I've checked, double, triple, quadrouple checked everything on the board itself.

I'm starting to wonder if somewhere in the transfer, my processor died...

Next I'd check the Power supply. It seems to be common still. A stretch but you've already covered a lot of ground so I'm trying to think of something you missed. After that the only other common denominator is the CPU and maybe the RAM.

Thats the problem if the processor does the same thing in different boards.

If the CPU is dead you should get some beeps to troubleshoot the problem.

I had the problem that PDXterra described once. I had to put insulation tape on all of the screw mounts under the motherboard. Only way to diagnose it was to actually pull the Motherboard out of the case and rest it on some card - while still attached to the On / Off button & PSU etc.

Please don't be offended because it sounds like you're a lot more experienced with these things than I was when I built my computer, but mine did the exact same thing. The problem was an unconnected power cable from the power supply to a plug near the video card.

Check again that you didn't leave the clear cmos jumper shorted

Disconnect the hard drive and try to get it to post, I have seen this happen before from a bad hdd controller (on the drive itself, not the mb)

Do either mobo's have a SLI shadow card you need to insert or mess with? Do you have the 4 pin auxillary power hookedup?

All of these are great ideas. Thanks for all the input guys. Only problem is, I've tried all of these except for buying a new processor.

All the power connectors are connected properly, the jumpers are all set where they should be. I've tested all three power supplies I tried with a Thermaltake Power Supply Tester as well as an Antec Power Supply tester All three PSU's came back working flawlessly, so it's not the PSU or how it's plugged into the boards.

I haven't tried running the motherboard out of the case completely to see if anything there is shorting out....I'll try that one...

As for a SLI shadow card....It's an 8x AGP motherboard, so there is no need for a shadow card.

Other than that, I'm almost thinking the CPU is dead

Do you have the book for the MB? Does it list what the beeps mean?

I've had memory cause something similar - memory is intimately tied to the processor - try the memory in another system.

Unfortunately you can kill some versions of the Athlon in a split second by overheating. If it is not dead, make sure your heat sink is attached securely - I use Arctic Silver paste to have a good connection.

Should deffinately try with CPU only - Zero RAM. Just to see if you get a boot screen. If you haven't already. Bad RAM wouldn't normally cause that type of problem tho. You'd just die loading Windows if it was bad RAM.

Thanks everyone for your input.

After some tinkering today, I got it to post! I have three computers currently working now. I had to remove my video card and sound card from my micro ATX computer case (running an Athlon XP 3000+) and fit it into the XP 3200+ machine.

Basically now, the micro ATX case that I was using as a backup gets a crappy sound card and on-board video for the time being. The computer that I couldn't get it to post is now running a 3200+ processor, 1.5gb ddr400, 80gb Seagate harddrive, nVidia 5900XT 128, and a SB Live 5.1 sound card. All three systems are working well now (with the exception of the SATA in my main machine ).

Thanks for all your help guys. In the end, it was a video card that went bad on me unknowingly....

Ha! I had a feeling that was the problem. Been there, done that

Didn't he say he swapped the vid card before?

I did. And it didn't work at that time. I'm not sure what happened and why it didn't work originally. At any rate, it works great now! All I need is another LCD and keyboard/mouse and I'll be ready to go with that computer.