DISK BOOT FAILURE error

I am working on a Compaq Presario desktop that died after a power failure. (yes, it was plugged in to a surge protector)

When it boots it gives a black screen and the message "Disk Boot Failure, Insert System Disk and Press Enter"

It seems to go through the POST ok (1 short beep), memory check ok, all devices listed as expected.

Here are all of the steps I've taken to correct/troubleshoot. ALL HAVE RESULTED IN THE SAME ERROR MESSAGE

Checked BIOS to make sure all drives are recognized and boot sequence is Floppy, CDROM, HDD
Tried booting off UBCD4Win
Tried booting off Maxtor Test Floppy
Tried booting off Gold Mem Test floppy
Pulled CMOS battery, reinstalled after 1 minute, checked all again
Pulled all ribbon cables from MoBo except floppy, tried to boot from floppy
Did same for HDD and CDROM
Swapped Memory with known good stick, repeated drive checks

Next I'm going to dig a PS out of my parts box and swap that, but ANY and all suggestions for next steps would be appreciated.

thanks
John

 

Just some other notes:

There are no external devices or connections to the PC, just PS KB and Mouse

Pulled all aux cards (just a PCI NIC), retested

 

So you get the 'DISK BOOT FAILURE' message even trying to boot to a CD or floppy? That's not good. Have you tried disconnecting the hard drive from both the power cable and the data cable, then booting to a CD or floppy? If you can boot into DOS from a Win98/MSDOS floppy with the hard drive unplugged, and then access a CD from DOS, then you know that your IDE controller on the MB is OK. If you can't browse a CD from DOS, or you can't boot to a CD with the HD unplugged, then you may have a bad IDE controller.

 

I've disconnected all ribbon cables from the MB and Power cables to the CDROMs and HDD, leaving just the floppy connected to the MB and powered.

Tried booting from both the Maxtor HD test floppy, and from Gold Test Memory tester floppy. Still get the error message.

I was hoping there was some other detail I was missing, but it seems more and more like the MB is bad.

thanks
John