Macbook Fails to Boot, no Apple Logo, any ideas?

Hi all,

I'm not sure if this might be a hardware or OS problem or this is in the right category, but I'm hoping someone can help me out with a problem I'm having with a friend's Macbook.

When I hit the power button, the chime plays, and the screen turns light gray or white, and then stays there. No apple logo, or spinning gear, no other icons, just gray. I've left it like this for a while and nothing happens.

If I hold Option to try and get a list of drives (with or without the install cd) it gives me a working mouse cursor, but never gives me any drives.

If I try safe mode, nothing happens, white screen, no change as long as I try it.

Same thing if I tried to boot from CD, the CD spins for a while, but then nothing.

Same for verbose mode.

If I try to reset the PRAM it does reboot correctly and chime again, but no other change.

It seems like these options are functioning, but nothing is working after that.

I've read that the missing logo might mean a problem with firmware, but I can't see any way to fix that without OS X installed.

Is it possible the HD has failed? Would that also explain the missing logo?
Any ideas from anyone with a similar problem? I've Google'd different variations of the problem, but can't find anything except problems with the Apple logo present.