Hey, I have had a nForce 590 SLI Mobo in my PC for a long while now.  It's always worked great until a couple weeks ago.  The computer will start up, however it will not display anything on the monitor and the on board LED code thing reads 29.  It just stays stuck on 29 and it won't do anything.  In the manual it states that code 29 is: "Chipset programming and CPU Speed detect"  I assume that had to do with overclocking, and my processor was overclocked, but I have tried four different AM2 proccessors in the computer, and none have worked.  I am letting the computer reset the CMOS right now.  I took out the battery and unplugged everything, but before I checked in the BIOS and it said it wasn't overclocked, yet it still showed that my CPU was.  Anyway, if the CMOS reset doesn't work, what do I do?  Is it time to get another mobo? 

Thanks for your help. =)

Update: So, I reset the CMOS and unplugged everything, and it worked... For about a day.  Now, my computer will start up for about 10 seconds and then shut down.  Could this be a bad CPU socket on my motherboard?  Could it be my power supply?  I'm pretty sure it's something on my mobo, but what? 

Please, I need some answers to get my computer fixed.  Thank you!  

Hm  make sure your heatsink is still attached and seating correctly, starting up and shutting down can be heat related.

Next I'd look at the power supply as the problems started when overclocked which draws more power then you got rid of the overclock and it worked for a day. Kind of points to the power supply going bad possibly.
Try this unplug the power from anything you do not essentially need like case fans as they will not do much with the case open anyways. Also unplug any extra hard drives and anything else that draws power that is not essential to the system starting and see if it starts for longer time.

Got another PSU you can test with, no need to take everything out of the case just plug the test power supply into your motherboard and anywhere else it is needed to be able to boot like the hard drive.