I have recovered a motherboard out of a machine that was dropped over a set of banisters(1 floor). The machine was retired due to the hard drive be totally broken and age(its only 800mhz, but good enough for my needs). I have tried installing both ubuntu 5.10 and Mandriva 2006; ubuntu freezes at the detecting network hardware screen and mandriva just after the add normal user screen.

I have tried different ubuntu disks and the mandriva ones have been used succesfully before, different CD drives and different network cards. There is no visible damage but whenever booted the the motherboard gives a warning about the memory settings being wrong even if the ram chips havent been touched.

Does this sound like a broken motherboard and if so is it FUBAR or salvageable?

Try reseating everything (processor, memory, etc). Afterthat, run the memtest from the installation cd of Mandriva (not sure if ubuntu has it).

Also, get into BIOS and verify that it's recognizing your hardware. If it is, then perhaps the issue is really just an installation problem rather than a mobo problem. Similarly, you might try booting up a Live CD like Knoppix, which runs off the CD rather than the hard drive.