Hello,
 
I finally got my computer parts and I've set up the Motherboard, 1 stick of RAM, Video Card, fans, and PSU up.  When I start it up, it'll make it to the Gigabyte MBoard screen with options: Tab for POST screen, DEL for BIOS Setup/Q-FLash, F9 for XpressRecovery2, F12 for Boot Menu, End for Qflash.
 
Initially I had a USB wireless keyboard and that didn't work, unsurprisingly.  I went out and bought a PS/2 to see if that would work, but it didn't.  The green Caps/Numlock lights flash when it's started, but after that nothing.  I tried searching for solutions, but couldn't find any for my specific problem.
 
Mainboard: GA-P35-DS3L
Processor: E8400
Vcard: Old Nvidia 6000 (My new one hasn't arrived)
 
I don't have the HD hooked up at the moment.

I've just started having a similar issue on an MSI P35 board.... it doesn't bother me much right now, because i already have settings how i want them, but It could be nuisance if I ever change processer or want to bios flash.... oddly, it used to work with the same keyboard but it just recently started not to.

I assume you plugged the PS/2 keyb in the green plug in the back of the pc. It should work, but you may have to disconnect power cord, wait 1 min, hook it up, and power on. PS/2 isn't plug-n-play. USB is.
 
BTW, I am using USB keyb/mouse no problems in bios, in dos, linux & windows. The key is to enable USB keyb/mouse. Or set them to BIOS/OS. Mine is on OS cuz my OS has the drivers for them. Oh yeah my mouse is wireless USB.

I had this happen once where a wireless wouldn't recognize, so I switched to a PS/2 and problem solved.  USB *should* be fine, but Enable it in the BIOS.  And yes, make sure the PS/2 is plugged into the green slot.
 
 
Hey Akhilles, how you been?  I've been MIA here for..............awhile.  Or more.

I've run into this problem occasionally, mainly with USB keyboards, which is why I keep a PS/2 keyboard around for setting up a computer. However, I've found that if a computer has been running fine for a time and then the keyboard stops working correctly, that's often a sign of a motherboard going bad.  
 
Since the trouble experienced here is with a new motherboard and it has failed with multiple keyboards, USB, wireless, and PS/2, then I'd suspect the motherboard is bad. Double check check all the wiring to make sure everything is plugged in correctly. Wouldn't want to blame the motherboard if there's a power line that isn't plugged in correctly.

sorry to partially hijack the thread, but mine was working fine with USB, and now isn't, so Sailer..... its going to die soon? it works absolutely fine in windows.... (i lack experience in this matter, USB has always worked for me )

Spuddy- I've had one motherboard that suddenly refused to recognize a USB keyboard no matter what I tried and it lived for years using a PS/2 keyboard. I've had two other motherboards fail with a USB keyboard and then go on to total failure within a short time. I questioned a couple of the local computer experts and they said that if the USB quits powering the keyboard adequately, there's trouble on the horizon, as it could fail to power other USB devices in the future. The failure rates affected early USB motherboards more than the recent ones, but its still a sign of bad times.  
 
I think its a thing to be aware of and if other troubles do begin, then a good place to start looking is the motherboard. On the other hand, if the motherboard will work fine with a PS/2 keyboard in every other way, I'd just accept that one deficiency and find better things for my time. So to answer your question, if "its going to die soon", I can't say. But it is something to be aware of in case other problems crop up..

ok, OP, you can have your thread back

Is it worth trying a regular non-wireless USB keyboard?  I'd have to go buy one.  The USB ports are powered, but I have no idea if they're enabled or not, since I can't get into the BIOS.

I double checked the PS/2 to make sure it works, since it's new.  It works fine for another computer.

if its a setting in the bios wouldn't resetting the CMOS help? (unless i am being my typical, absent minded self and have missed something completely obvious)

I've tried resetting it.

Do you think it could be a bad motherboard, should I get it replaced?

 
Generally speaking, a wired USB keyboard is more dependable that a wireless keyboard, while a PS/2 keyboard is the most dependable. If a PS/2 keyboard doesn't work, and its verified to work on a different computer, I'd say that there's a problem with the motherboard.  
 
Reading back, I see that the hard drive wasn't hooked up yet. Try hooking the drive up and see if anything changes. Its possible that the BIOS is looking for the hard drive and not finding it, it then shuts down everything else, preventing the keyboard from being used at the same time. I've never done a build without the hard drive installed as I first started the machine, so I can't tell what the result would be by my experience.

I just tried with 2 different hard drives.  A new one and another that I know works.  The keyboard still won't work.

At this point, the finger points to the motherboard as the culprit. Assuming that the motherboard is new, return it to the store or RMA it as the case may be. But when the other parts are verified as good, the remaining part is the logical bad one.

The only other part that can't test with something else is the processor.

It can be safely said that the processor has nothing to do with the keyboard problem, as well as the ram or the video card.

I have had one ps/2 keyboard that would work with a mobo, but not the other. It's a very rare case. If your USB devices don't work, try another port or even external hub.
 
skyguy, you're the one who's been MIA since I've been back.

Hi all.  I am having a similar issue.  Two keyboards; one USB, the other ps/2.  Both work on other computers, and both work in the Vista OS
Weird problem; as I enter BIOS with USB keyboard attached, the clock shows ticking, but with the first key press, the clock freezes (I guess the whole BIOS does), and keybord lights get stuck.
PS/2 keyboard has the same issue, but I am able to jump around the BIOS menus for about 1-2 minutes before it freezes up as well.
 
??? Should I take the mobo back to store?  They checked it out for me when I bought the mobo and their keyboard worked fine in BIOS.

Before going through the trouble of returning your motherboard, check your PSU. I just recently had the same problem and found that my PSU was faulty or about to die. Neither PS/2 or USB keyboards would work for me unless I unplugged the power to everything except my motherboard. If my hard drive or CD drives were plugged in, my PSU couldn't supply enough power to the entire system, including the keyboard. I doubt this will be the problem but it won't hurt to try.