Not sure it would impact the current problem, but is this an OEM board, rather than Intel retail? - the altered assembly number (685012-509) doesn't appear in the last cumulative spec update for the board which might suggest OEM. What it does indicate is that all the xxxxxx-509 series boards are early production versions which likely shipped with matching BIOS versions - possibly around P03 (you'll need at least P08 for PII 333MHz support).
Jumper J7E1 set to pins 2-3 should force the system to the setup menu where you can set the actual installed processor speed (if the damn thing would only start!). Although it supportred 233, 266, 300MHz from the get-go, it might have issues with specific steppings of those speeds if you're on an early BIOS revision (see the attached BIOS history).
The way I read the manual, the auxilliary power connector is optional by default, but recommended for heavy load setups
Some heavily loaded configurations could require additional +3.3 V and +5 V power for peripherals. Use the auxiliary power connector at J1M2 for this purpose."
Other than that, the only defaults seem to be the main processor is always in the rear slot 1 position, with a terminator board in the secondary slot 1 position if not in dual processor mode and that memory can be 3.3V unbuffered 66-MHz ECC/non-ECC SDRAM or 60-ns EDO ECC/non-ECC DIMMs (100MHz DIMM support added in BIOS P10) with a max of 128MB SDRAM or 256MB EDO per memory slot.