See if you have the B3T.exe on your hard drive. This is a BMDC test piece of software.
Try running that.
I have been looking at the schematics. i would look harder for CR1. it seems to put power to the Pwmint board which turns on the drives. Check the overloads in the top left hand corner of the machine as well. (page 3 of the schematics)
If the CMOS is corrupted then the PC side of the machine will not be able to read the hard drive correctly and thus load the software to the BMDC and to memory. Same if the hard drive has some scrambled software. Check the CMOS and try going to the DOS directory and running SCANDISK and DEFRAG.