I bought a dual pentium 4 motherboard off eBay, and encountered this problem of the BIOS POST not completing; a test card displaying the Award BIOS code 7Fh; waiting for operator input of either F1 or DEL...but the system being unresponsive to keyboard input, period.

The supplier concluded it was a fluke, and the motherboard was dead on arrival (DOA) so sent me a second SuperMicro P4DC6+ motherboard. After switching boards, checking all jumpers, reconnecting hardware, etc. I started it up. The same thing happens!

I know the keyboard I was using is good, but I replaced it with a new spare; same result. I've messed with the keyboard wakeup (both PS/2 and USB) jumper settings, but the result is always the same. The SuperMicro logo is displayed on the first BIOS screen, the prompt to press DEL to enter setup or TAB to display POST messages appearing below...pressing DEL at this point multiple times, or holding it steady, does not take me into the BIOS setup program. It only moves to the second screen, displaying a text report of POST progress...reporting on the main CPU, the memory is okay, the master and slave drives, the fact that the CPUs have been changed:

CMOS checksum error - Defaults loaded
Warning! CPU has been changed
Please re-enter CPU settings in the CMOS setup and remember to save before quit!

Then some blank space, and the prompt at the bottom of the screen:

Press F1 to continue, DEL to enter SETUP
09/26/2001-i860-W83627-6A69SSXAC-00

...and pressing either F1 or DEL produces no response. I cannot get into SETUP!

I will appreciate helpful clues to debug this issue!

Aloha.

This is more likely an issue with your processor since it does the same thing in two boards. Either that or the board doesn't support whatever processor you're trying to put into it. This is a very old board.

What processor are you trying to put in it? This board is Socket 603 and designed only for Xeon processors.

The supplier and I thought that, given the sequence of POST codes ending in 7Fh, the motherboard circuits for the 2nd processor were implicated (though there had been no problem with the motherboard, 1.5 GB ECC memory, or both 2.4 GHz Xeon processors prior to his upgrading that system for his client). But could that be true with the second board (also working before he upgraded another client), too? Unlikely. To my mind, it seems like the keyboard is dead, and not communicating with the BIOS; or, the BIOS is ignoring keyboard inputs.

Yes, the board is old...the same age, about, as my former SuperMicro P3TSSA Pentium III board that decided to die. Since I am building an AMD dual Opteron processor workstation, I figured the dual Pentium IV board will be sufficient for my backup computer, used rarely. However, this experience is shifting me in the direction of always preferring new(er) boards!

I have seen the errors you are getting on the NT units I work on. The error on my units is usually the battery being dead/ low. I have also seen it be the CPU board.
And it wants you to enter bios to set the clock.
The problem being (as stated) you cant get there.

During POST, do the lights on the keyboard flash? Probably not. Bios is looking for the keyboard at this time.
Usually if post does not find a keyboard, you will get "keyboard not present" error.

We need to isolate the problem.
What is the only thing different between the 2 boards?
I assume you are using the same PSU, processor, hard drive, and ram. It is unlikely that bios is messed up on 2 different boards.

I suspect the processor.

The battery is new, the keyboard lights do flash briefly during the initial checks. The POST process proceeds through checking the processors and the memory, then states the cpus have been changed so the BIOS loaded defaults. Then it hung, waiting for keyboard input (either F1 to continue, or DEL to enter setup).

Well, I decided to double check all connectors (which meant some disassembly of the chassis, removing a couple of drives--the 3.5" floppy and another--then removing the cage that holds them so I could get to the motherboard underneath. I'm red-green colorblind, more troublesome in certain low-level light than in bright light. It turns out I had connected the two terminals (+ and -) for the keyboard lockout detection to the wrong pins (the right ones for a different color wire). The POST process was detecting that the keyboard was locked out, but couldn't tell me that because it needed keyboard input to proceed to the point where it could tell me that!

Ah, the strange ways of computers. :-) With those wire terminals repositioned, the keyboard worked, I was able to enter DEL to get into SETUP, and confirmed all the settings. So I'm almost there in recovering my windows xp system. Due to the new motherboard and chipset, I think, windows reported a problem with a missing or corrupted c:\system32\ntfs.sys file. The bootable DOS floppies I've had for years all won't load, so my next step is to create a new floppy with freeDOS. I ran out of time, so will do this in another day or so.

Thanks for letting us know. It does sound like progress.