8300 does not boot

I attempted to turn my Dinension 8300 on today, and the power light came on. The LEDs for the DVD-ROM and DVD-RW came on as normal (but not the one for the floppy drive), and then nothing. No POST, no nothing. The monitor doesn't even come out of standby mode. The LEDs at the back of the computer are YYGG (for ABCD), but the funny thing is that the power LED is still a steady green. Not sure what's going on, since everyone else with that set of lights seems to have an amber light. Hope someone can help!