[gijoe77]

first things first you have a ps/2 mouse and keyboard plugged in? If you don't it might try to come up headless.
2nd - do you hear a little chime when you first turn it on? I would really think you would see the PROM screen, it's troubling that you don't - it might very well be a cabling/adapter issue.
3rd - you will absolutely need to have a serial cable, perhaps there is a issue and with console access it may be of help
4th - do you know if the seller setup a network? something like 192.168.1.XXX or whatever people tend to set as the default? If the system is coming up, and the network is up, you might be able to log in remotely and try a few commands to try a different resolution.