Error 43 is sort of like a "check engine" light on a car. It tells you there is trouble but nothing specific. There are two different processors(166mhz or 300mhz) used during production of the d8b. Are you sure you have set the BIOS for the correct processor? Is the motherboard battery good? If not, the correct settings you just set for BIOS can go away as soon as you power down, leading to an Error 43 on the next boot up.
I would also be suspect of bad RAM as a possible issue. Has this unit ever worked for you? Have you made any changes recently that have gotten you to this point of non-boot?