Beige G3 MT 300 woes

I know you know all this, but is are the IDE cables and Ram seated well? It was working great when I packed it up. The last thing I did with it was create a generic user account and delete the one i was using.

pull out the cd-rom from your other beige and boot from that?

When you say it won't boot from onboard video, do you mean you don't see anything at all, not even a grey screen, or you reached that point and can't get it to see the hard drive?
I bought a DT G3, also from someone on here on Applefritter, and it didn't work on arrival. I had to reseat the CPU and remove and clean the hard drive's circuit board. The drive had escaped its rails during shipping and wandered around the case tethered to its cable, knocking the heatsink right off the CPU. Some compressed air and new thermal grease and it's worked like a charm ever since.

A bit of advice to others buying computers online: boot it stock first, test it, then start adding your own goodies, mods, etc. That way you know it did/didn't work on arrival, and your own modifications haven't messed things up (not to say at all that any of that is the case here, or to imply fault on either party). Also get these things shipped insured.

I cured it somewhat, im still gonna take it down to the UPS Hub to show them the damage the box was in. mind you it wasnt packed very well. the thing with it is, is it dont like a video card in it is all. Once i attached a monitor to the onboard video it cleared up, i just didnt get os x to boot, so i wiped it and reinstalled panther, although the hard drive did have some bad blocks on it from shaking around and i had to reseat everything. Mind you the UPS delivery guy just threw it down on the ground.