I'd try removing everything but the hard disk on ide cable. then try booting. Master should be at end of cable.
if no results after straighting the cable and twisting it to ensure "flatness", replace with another cable.
try removing powersupply and plugging it back in.
try pressing Amiga+Amiga+CTRL, could be the hard drives are too fast? Try booting with OS 3.1 or your OS 3.9 emergency system disk and then using hard disk tools to see if you can "see" any hard disk?
