HELP - HP Pavilion - black screen - won't boot

Hi,

I recently purchased an HP Pavilion 9694c series system for my kids to use.
The thing seems to have some s/w issues so I was on the verge of wiping the
system clean and reloading the default environment (Win98SE + all the
preloaded stuff). Last night my son powered up the system and it apparently
hung after the desktop appeared. He says he shutdown the system with
ctrl-alt-del, ctrl-alt-del. When I walked into the room he was unplugging
the power strip from the wall socket!

Now when I power on the system I don't get anything displayed on the
monitor, not even the BIOS splash screen. I have a black screen but the
power light on the monitor is a solid green. It sounds like the hard drive
spins up. The hard drive light comes on and stays on. The CD light blinks.

I have tried a number of things (some were my own doing and others were
suggested on the HP website and from email with HP tech support), all to no
avail. I would greatly appreciate some sage advice before I start replacing
parts (something I know little to nothing about) or junking the system.

Steps I've already taken :
1) Tried many more times.
2) Hooked the computer up to another monitor (easier than hooking monitor to
another computer.
3) I stuck a bootable floppy in the floppy drive and restarted the system.
It doesn't appear as though the floppy is being accessed.
4) Tried resetting the BIOS to default configuration. I'm not sure if this
worked because the instructions said to hit F1 after the keyboard turned on.
None of the keyboard lights come on when I power up so my timing may have
been off if the system ever got far enough to let me into setup. I tried
numerous times to try and cover the timing issue.
5) I disconnected the IDE cable from the hard drive, rebooted, shutdown,
reconnected the cable and booted again. While at it I also reseated the
video card and checked the IDE connectors on the motherboard and CD and DVD
drives.

I am assuming that I have a h/w problem but I'm not sure where to start. Is
it the BIOS? If so, can I replace just the BIOS? Could the power supply be
the culprit? If so, that would mean that it still powers some components but
not others. Is this possible? Thanks in advance.

-- Wes